ci: bump actions/cache from 3 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 3 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v3...v4)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/build_documentation.yaml

@@ -94,7 +94,7 @@ jobs:
           python-version: '3.x'
 
       - name: Restore Python Dependencies
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         id: cache_python
         with:
           path: ~/.cache/pip
@@ -107,7 +107,7 @@ jobs:
 
       - name: Restore Doxygen, Graphviz, and TeX Live
         id: cache_doxygen
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: |
             /usr/lib/x86_64-linux-gnu/texlive

.github/workflows/build_examples.yaml

@@ -126,7 +126,7 @@ jobs:
         uses: arduino/[email protected]
 
       - name: Restore Arduino platforms and libraries
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         id: cache_libraries
         with:
           path: |
@@ -197,7 +197,7 @@ jobs:
         run: pip install -r continuous_integration/requirements.txt
 
       - name: Restore PlatformIO and Arduino platforms and libraries
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         id: cache_libraries
         with:
           path: |