ci: add weekly cache rotation for fresh builds

Author: xdustinface

.github/workflows/build-and-test.yml

@@ -18,10 +18,13 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
+      - name: Get cache week
+        id: cache-week
+        run: echo "week=$(date +%Y-%W)" >> $GITHUB_OUTPUT
+        shell: bash
       - uses: Swatinem/rust-cache@v2
         with:
-          prefix-key: "v1-rust"
-          shared-key: "${{ inputs.os }}"
+          shared-key: "${{ steps.cache-week.outputs.week }}-${{ inputs.os }}"
           cache-on-failure: true
       - name: Build workspace
         run: cargo build --workspace --all-targets --all-features ${{ inputs.exclude-crates && format('--exclude {0}', inputs.exclude-crates) || '' }}
@@ -37,10 +40,13 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
+      - name: Get cache week
+        id: cache-week
+        run: echo "week=$(date +%Y-%W)" >> $GITHUB_OUTPUT
+        shell: bash
       - uses: Swatinem/rust-cache@v2
         with:
-          prefix-key: "v1-rust"
-          shared-key: "${{ inputs.os }}"
+          shared-key: "${{ steps.cache-week.outputs.week }}-${{ inputs.os }}"
           save-if: false
       - uses: actions/setup-python@v5
         with: