chore(deps): update actions/cache action to v4 (#7047)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/actions/install-all-deps/action.yml

@@ -32,7 +32,7 @@ runs:
       run: |
         python -m pip install --upgrade virtualenv
         python -m virtualenv venv
-    - uses: actions/cache@v3
+    - uses: actions/cache@v4
       id: cache
       with:
         path: |

.github/actions/install-frontend-deps/action.yml

@@ -18,7 +18,7 @@ inputs:
 runs:
   using: "composite"
   steps:
-    - uses: actions/cache@v3
+    - uses: actions/cache@v4
       id: frontend-cache
       with:
         path: |

.github/workflows/backend.yml

@@ -78,7 +78,7 @@ jobs:
         path: |
           client/python/venv/*
         key: python-client-${{ runner.os }}-pip-${{ hashFiles('client/python/requirements.txt') }}-${{ hashFiles('client/python/test/requirements.txt') }}
-    - uses: actions/cache@v3
+    - uses: actions/cache@v4
       id: frontend-cache
       with:
         path: |
@@ -166,13 +166,13 @@ jobs:
       run: |
         python -m pip install --upgrade virtualenv
         python -m virtualenv venv
-    - uses: actions/cache@v3
+    - uses: actions/cache@v4
       id: cache
       with:
         path: |
           venv/*
         key: gradio-lib-${{ runner.os }}-pip-${{ hashFiles('client/python/requirements.txt') }}-${{ hashFiles('requirements.txt') }}-${{ hashFiles('test/requirements.txt') }}
-    - uses: actions/cache@v3
+    - uses: actions/cache@v4
       id: frontend-cache
       with:
         path: |