chore(actions): update actions/cache action to v4

Author: renovate[bot]

.github/workflows/docs.yaml

@@ -71,7 +71,7 @@ jobs:
 
     - name: Cache pip dependencies
       id: cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.cache/pip
         key: ${{ runner.os }}-pip-${{ hashFiles('pyproject.toml') }}

.github/workflows/pull_request.yml

@@ -24,7 +24,7 @@ jobs:
 
     - name: Cache pip
       id: cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.cache/pip
         key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
@@ -58,7 +58,7 @@ jobs:
 
     - name: Cache pip dependencies
       id: cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.cache/pip
         key: ${{ runner.os }}-pip-${{ hashFiles('requirements-docs.txt') }}