ci: limit clippy --tests to one representative target

.github/workflows/rust-ci.yml

@@ -145,6 +145,8 @@ jobs:
           - runner: windows-arm64
             target: aarch64-pc-windows-msvc
             profile: dev
+            # This is consistently the slowest test job; keep runtime coverage on pushes/manual runs.
+            skip_on_pr: true
             runs_on:
               group: codex-runners
               labels: codex-windows-arm64
@@ -387,8 +389,20 @@ jobs:
           cargo chef prepare --recipe-path "$RECIPE"
           cargo chef cook --recipe-path "$RECIPE" --target ${{ matrix.target }} --release --all-features
 
+      # Cargo timings show `--tests` repeatedly rebuilding heavy test targets
+      # (especially codex-core) across the full matrix. Keep test linting on one
+      # representative dev target and let nextest continue compiling tests on the
+      # runtime test matrix.
       - name: cargo clippy
-        run: cargo clippy --target ${{ matrix.target }} --all-features --tests --profile ${{ matrix.profile }} --timings -- -D warnings
+        shell: bash
+        run: |
+          set -euo pipefail
+          args=(cargo clippy --target "${{ matrix.target }}" --all-features --profile "${{ matrix.profile }}")
+          if [[ "${{ matrix.profile }}" == 'dev' && "${{ matrix.target }}" == 'x86_64-unknown-linux-gnu' ]]; then
+            args+=(--tests)
+          fi
+          args+=(--timings -- -D warnings)
+          "${args[@]}"
 
       - name: Upload Cargo timings (clippy)
         if: always()
@@ -577,6 +591,7 @@ jobs:
             sccache-${{ matrix.runner }}-${{ matrix.target }}-${{ matrix.profile }}-
 
       - uses: taiki-e/install-action@44c6d64aa62cd779e873306675c7a58e86d6d532 # v2
+        if: ${{ !(github.event_name == 'pull_request' && matrix.target == 'aarch64-pc-windows-msvc') }}
         with:
           tool: nextest
           version: 0.9.103
@@ -594,6 +609,7 @@ jobs:
 
       - name: tests
         id: test
+        if: ${{ !(github.event_name == 'pull_request' && matrix.target == 'aarch64-pc-windows-msvc') }}
         run: cargo nextest run --all-features --no-fail-fast --target ${{ matrix.target }} --cargo-profile ci-test --timings
         env:
           RUST_BACKTRACE: 1