ci: fix cache-key collisions and skip duplicate release-commit test run

The test job and build-linux shared one cargo cache key; the test job's
debug artifacts claimed it first and actions/cache skips saving on an
exact-key hit, so Linux release builds compiled cold every time (~31min
vs ~9min for the correctly-keyed Windows job). Same collision between
android-check and build-android. Give the release jobs their own keys.

Also skip build-and-test.yml for chore(release) commits: the tag push
triggers build-release.yml on the same commit, which runs the identical
test suite, and the two ~1h workflows contended for the single runner
slot.

.gitea/workflows/build-release.yml

@@ -88,6 +88,11 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      # ⚠️ Key must NOT collide with the test job's `cargo-host` key: the test
+      # job runs first and saves debug/clippy artifacts under its key, and
+      # actions/cache skips saving on an exact-key hit — so a shared key meant
+      # this job's *release* artifacts were never cached and every Linux release
+      # build compiled cold (~31min vs ~9min for the correctly-keyed Windows job).
       - name: Cache Rust dependencies
         uses: actions/cache@v3
         with:
@@ -95,9 +100,9 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             src-tauri/target
-          key: ${{ runner.os }}-cargo-host-${{ hashFiles('**/Cargo.lock') }}
+          key: ${{ runner.os }}-cargo-linux-release-${{ hashFiles('**/Cargo.lock') }}
           restore-keys: |
-            ${{ runner.os }}-cargo-host-
+            ${{ runner.os }}-cargo-linux-release-
 
       - name: Cache Node dependencies
         uses: actions/cache@v3
@@ -220,9 +225,13 @@ jobs:
             ~/.cargo/registry
             ~/.cargo/git
             src-tauri/target
-          key: ${{ runner.os }}-cargo-android-${{ hashFiles('**/Cargo.lock') }}
+          # `-release` suffix keeps this distinct from build-and-test.yml's
+          # android-check key, whose `cargo check` artifacts would otherwise
+          # claim the key first and block this job's release cache from ever
+          # being saved (same collision as the Linux job above).
+          key: ${{ runner.os }}-cargo-android-release-${{ hashFiles('**/Cargo.lock') }}
           restore-keys: |
-            ${{ runner.os }}-cargo-android-
+            ${{ runner.os }}-cargo-android-release-
 
       - name: Cache Node dependencies
         uses: actions/cache@v3