fix: bump rust cache format

.gitea/actions/rust-cache/action.yml

@@ -11,6 +11,10 @@ inputs:
     description: Prefix for cache keys.
     default: rust
     required: false
+  cache-version:
+    description: Cache format version. Bump this to avoid reusing stale or partial cache entries.
+    default: v2
+    required: false
 
 outputs:
   cache-hit:
@@ -37,8 +41,8 @@ runs:
         } > /tmp/rust-cache-fingerprint
         HASH=$(sha256sum /tmp/rust-cache-fingerprint | cut -d' ' -f1)
         echo "hash=$HASH" >> $GITHUB_OUTPUT
-        echo "key=${{ inputs.cache-prefix }}-$OS-$ARCH-${{ inputs.toolchain }}-$HASH" >> $GITHUB_OUTPUT
-        echo "restore-prefix=${{ inputs.cache-prefix }}-$OS-$ARCH-${{ inputs.toolchain }}-" >> $GITHUB_OUTPUT
+        echo "key=${{ inputs.cache-prefix }}-${{ inputs.cache-version }}-$OS-$ARCH-${{ inputs.toolchain }}-$HASH" >> $GITHUB_OUTPUT
+        echo "restore-prefix=${{ inputs.cache-prefix }}-${{ inputs.cache-version }}-$OS-$ARCH-${{ inputs.toolchain }}-" >> $GITHUB_OUTPUT
 
     - name: Restore Rust cache
       id: cache-restore