Update actions/cache action to v4

Author: renovate[bot]

.github/workflows/update-l10n-sources.yml

@@ -19,7 +19,7 @@ jobs:
           python-version: "3.7"
 
       - name: Restore pip cache 💾
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}

.github/workflows/update-l10n.yml

@@ -19,7 +19,7 @@ jobs:
           python-version: "3.7"
 
       - name: Restore pip cache 💾
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}