Bump actions/cache from 3 to 4 (#594)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/main.yml

@@ -28,24 +28,24 @@ jobs:
           echo ::set-output name=PYRIGHT_VERSION::$(grep '"pyright"' .github/package.json | cut -d\" -f4)
         id: read_versions
       - name: Cache pyenv
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: |
             ~/.pyenv
             !~/.pyenv/versions
           key: pyenv-installation-2
       - name: Cache pyenv mypy-protobuf ver
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.pyenv/versions/${{matrix.py-ver-mypy-protobuf}}
           key: pyenv-${{matrix.py-ver-mypy-protobuf}}-${{hashFiles('setup.py')}}
       - name: Cache pyenv unit tests 3 ver
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.pyenv/versions/${{env.PY_VER_UNIT_TESTS_3}}
           key: pyenv-${{env.PY_VER_UNIT_TESTS_3}}-${{hashFiles('setup.py')}}
       - name: Cache pyenv mypy ver
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.pyenv/versions/${{env.PY_VER_MYPY}}
           key: pyenv-${{env.PY_VER_MYPY}}-${{hashFiles('setup.py')}}