ci(e2e-go): strip indent + file:line on display, propagate color env over SSH

Two display bugs spotted on the previous run:

1. Phase banners came out white instead of bold-cyan because the test
   binary runs over SSH on the tofu VM, where neither GITHUB_ACTIONS
   nor a TTY is present, so harness.log.go init() disables ANSI escapes.
   Fix: export GITHUB_ACTIONS=true and FORCE_COLOR=1 in the remote env
   so the helper keeps emitting color codes.

2. Every t.Logf line still rendered as
       lb_test.go:61: instance type: t3.nano
   (4-space indent + `<file>:<line>:` prefix) because t.Helper()
   bubbles file:line to the call site. Fix: pipe the test binary's
   stdout through `sed -E 's/^[[:space:]]+([a-zA-Z0-9_]+_test\.go:[0-9]+: )?//'`
   so the display strips both. Tee to the artifact log happens BEFORE
   the sed so raw output is preserved for triage; only the live UI
   sees the cleaned form.

.github/workflows/e2e-go.yml

@@ -169,10 +169,11 @@ jobs:
              for SUITE in ${SUITES_RUN}; do \
                echo \"::group::suite \$SUITE\"; \
                printf '\n%s%s━━ suite %s ━━%s\n' \"\$B\" \"\$C\" \"\$SUITE\" \"\$R\"; \
-               SPINIFEX_E2E=1 SPINIFEX_MODE=single \
+               GITHUB_ACTIONS=true FORCE_COLOR=1 SPINIFEX_E2E=1 SPINIFEX_MODE=single \
                  ARTIFACT_DIR='${ARTIFACT_DIR}' \
                  ./\$SUITE.test -test.v -test.timeout=30m \
-                 2>&1 | tee '${ARTIFACT_DIR}/test-'\$SUITE'.log'; \
+                 2>&1 | tee '${ARTIFACT_DIR}/test-'\$SUITE'.log' \
+                      | sed -E 's/^[[:space:]]+([a-zA-Z0-9_]+_test\.go:[0-9]+: )?//'; \
                rc=\${PIPESTATUS[0]}; \
                echo \"::endgroup::\"; \
                if [ \$rc -ne 0 ]; then \