chore(deps): update actions/cache action to v5

Author: renovate[bot]

.github/actions/docusaurus-cache/action.yaml

@@ -4,7 +4,7 @@ description: "Cache Docusaurus for faster application rebuilds."
 runs:
   using: "composite"
   steps:
-    - uses: actions/cache@v4
+    - uses: actions/cache@v5
       with:
         path: |
           ${{ github.workspace }}/.docusaurus

.github/actions/muffet/action.yaml

@@ -27,7 +27,7 @@ runs:
         echo "Muffet version  : ${{ inputs.muffet_version }}"
         echo "URL to validate : ${{ inputs.url_to_validate }}"
     - name: Restore cache
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       id: tool-cache-muffet
       with:
         path: /usr/local/bin/muffet

.github/workflows/links.yml

@@ -27,7 +27,7 @@ jobs:
 
       - name: Restore lychee cache
         id: cache-restore
-        uses: actions/cache/restore@v4
+        uses: actions/cache/restore@v5
         with:
           path: .lycheecache
           key: cache-lychee-${{ env.DATEOFDAY }}