ci: drop the docker layer cache and stop installing unused tooling (#5544)

Two cleanups, neither changing what is built or published.

docker.yml loses its type=gha layer cache. The image build compiles nothing —
it downloads a release zip and runs apk/apt — so the cache could only save the
minute or two those take, against a real correctness problem: with
RELEASE=latest the binary URL is resolved by curl inside a RUN layer, and the
layer key does not include what it resolved to. A rebuild at the same RELEASE
value (a dispatch with version=latest, or a re-run of the same version) would
hit the old layer and ship the previous release's binary. mode=max also drew on
the same repo-wide 10GB Actions cache quota the Rust lanes are contending for.

Only RELEASE is passed as a build-arg now; it is the sole one the Dockerfiles
declare besides TARGETARCH. BUILDTIME, VERSION, BUILD_TYPE, REVISION and CHANNEL
were read by no stage, and BUILDTIME's $(date ...) was a literal string in the
YAML block rather than a substitution. The DOCKER_CHANNEL computation that fed
CHANNEL evaluated to "release" down every branch and is gone with it. BUILD_DATE
and VCS_REF stay unset even though the Dockerfiles declare them: supplying them
would change the published image labels.

The setup composite stops installing tools its callers do not use. protobuf-
compiler comes out of the apt list entirely — setup-protoc installs 34.1 into
the tool cache and prepends it to PATH, so the apt build was shadowed on every
run and never used; the same duplicate install is removed from the io_uring lane.
musl-tools, zip and unzip move behind install-build-packaging-tools, off for the
CI and coverage lanes and left on for build.yml, whose native musl leg needs
musl-gcc and whose packaging steps need zip. cargo-nextest and the
rustfmt/clippy components move behind install-test-tools, off only for build.yml,
which runs no tests and no lints; coverage and the nightly replication lane keep
them because both invoke nextest.

The action's github-token input is deleted along with its 20 call sites. Its
runs block never referenced it — setup-protoc uses github.token directly — so it
was 20 places handing a token to something that ignored it.

Refs: rustfs/backlog#1598, rustfs/backlog#1600, rustfs/backlog#1603

.github/workflows/ci.yml

@@ -185,8 +185,8 @@ jobs:
           # rust-cache's post step, so writing from here saved nothing (12 of 15
           # consecutive main-push runs were cancelled). See rustfs/backlog#1600.
           cache-shared-key: ci-dev
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
 
       - name: Prepare test evidence
         run: |
@@ -359,8 +359,8 @@ jobs:
         with:
           rust-version: stable
           cache-shared-key: ci-dev
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
 
       # test_transition_and_restore_flows was re-enabled by rustfs/backlog#1303:
       # its "missing xl.meta on disk2" was a test-util bug (open_disk hardcoded
@@ -397,8 +397,8 @@ jobs:
         with:
           rust-version: stable
           cache-shared-key: ci-feat-rio
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
 
       - name: Run rio-v2 clippy lints
         run: cargo clippy -p rustfs -p rustfs-ecstore --all-targets --features rio-v2 -- -D warnings
@@ -439,8 +439,8 @@ jobs:
         with:
           rust-version: stable
           cache-shared-key: ci-feat-proto
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
 
       - name: Run clippy with ${{ matrix.features.name }}
         run: |
@@ -468,7 +468,7 @@ jobs:
           rust-version: stable
           cache-shared-key: ci-dev
           cache-save-if: 'false'
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          install-build-packaging-tools: 'false'
 
       - name: Build debug binary
         run: cargo build -p rustfs --bins --features e2e-test-hooks
@@ -499,7 +499,7 @@ jobs:
           rust-version: stable
           cache-shared-key: ci-feat-rio
           cache-save-if: 'false'
-          github-token: ${{ secrets.GITHUB_TOKEN }}
+          install-build-packaging-tools: 'false'
 
       - name: Build debug binary with rio-v2
         run: cargo build -p rustfs --bins --features rio-v2,e2e-test-hooks
@@ -546,11 +546,8 @@ jobs:
           # instead of this lane's ~1.3GB. cache-warm.yml warms this key on
           # ubuntu-latest for the same reason.
           cache-shared-key: ci-uring
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
-
-      - name: Install build dependencies
-        run: sudo apt-get update && sudo apt-get install -y protobuf-compiler
+          install-build-packaging-tools: 'false'
 
       # ext4 supports O_DIRECT; the runner's default TMPDIR may sit on tmpfs or
       # overlayfs, where open(O_DIRECT) returns EINVAL/EOPNOTSUPP and the native
@@ -606,8 +603,8 @@ jobs:
         with:
           rust-version: stable
           cache-shared-key: ci-dev
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
 
       # Download after the cache restore so the freshly built binary from the
       # build job always wins over anything restored into target/debug.
@@ -687,8 +684,8 @@ jobs:
         with:
           rust-version: stable
           cache-shared-key: ci-dev
-          github-token: ${{ secrets.GITHUB_TOKEN }}
           cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
 
       # Download after the cache restore so the freshly built binary from the
       # build job always wins over anything restored into target/debug.