build: upgrade Rust baseline to 1.96.0 (#3291)

* build: upgrade Rust baseline to 1.96.0

* ci: pin Rust workflows to 1.96.0

* remove

* ci: pin setup action to Rust 1.96.0

* build: pin toolchain to Rust 1.96.0

.github/workflows/ci.yml

@@ -54,7 +54,7 @@ on:
       - ".github/workflows/audit.yml"
       - ".github/workflows/performance.yml"
   merge_group:
-    types: [checks_requested]
+    types: [ checks_requested ]
   schedule:
     - cron: "0 0 * * 0" # Weekly on Sunday at midnight UTC
   workflow_dispatch:

.github/workflows/nix.yml

@@ -49,7 +49,7 @@ jobs:
       contents: read
       id-token: write
     env:
-      NIX_CURL_FLAGS: -A cargo/1.95.0
+      NIX_CURL_FLAGS: -A cargo/stable
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6