Cache only cargo-xwin and its SDK files for the Windows build

.gitea/workflows/release.yaml

@@ -40,18 +40,18 @@ jobs:
           # After a change to mise.toml, start from the last tools; mise installs only what changed.
           restore-keys: |
             tools-
-      # What only the Windows build needs. It is restored after the tool cache, so these
+      # cargo-xwin, which takes minutes to compile, and the Windows SDK files it downloads.
-      # folders are added to it. ~/.cache/cargo-xwin holds the Windows SDK files cargo-xwin downloads.
+      # The Windows Rust target is left out: rustup lists its installed parts in a file in
-      - name: Restore Windows tool cache
+      # the tool cache, and refuses to install the target over files that list does not name.
+      - name: Restore cargo-xwin cache
         uses: actions/cache@v4
         with:
           path: |
             ~/.cargo/bin/cargo-xwin
-            ~/.rustup/toolchains/*/lib/rustlib/x86_64-pc-windows-msvc
             ~/.cache/cargo-xwin
-          key: windows-tools-${{ hashFiles('scripts/ci-setup.sh', 'mise.toml') }}
+          key: cargo-xwin-${{ hashFiles('scripts/ci-setup.sh', 'mise.toml') }}
           restore-keys: |
-            windows-tools-
+            cargo-xwin-
       - name: Restore build cache
         uses: actions/cache@v4
         with: