Bump actions/cache from 2 to 3

Bumps [actions/cache](https://github.com/actions/cache) from 2 to 3.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](actions/cache@v2...v3)

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

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

Author: dependabot[bot]

.github/workflows/tests.yml

@@ -115,31 +115,31 @@ jobs:
           esac
 
       - name: Cache pip
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         if: startsWith(runner.os, 'Linux')
         with:
           path: ~/.cache/pip
           key: ${{ matrix.os }}-py${{ matrix.python-version }}-pip-${{ hashFiles('requirements/*/*.txt') }}
           restore-keys: |
             ${{ matrix.os }}-py${{ matrix.python-version }}-pip-
       - name: Cache pip
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         if: startsWith(runner.os, 'macOS')
         with:
           path: ~/Library/Caches/pip
           key: ${{ matrix.os }}-py${{ matrix.python-version }}-pip-${{ hashFiles('requirements/*/*.txt') }}
           restore-keys: |
             ${{ matrix.os }}-py${{ matrix.python-version }}-pip-
       - name: Cache ccache
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: |
             ~/.ccache
           key: ${{ matrix.os }}-py${{ matrix.python-version }}-ccache-${{ hashFiles('src/*') }}
           restore-keys: |
             ${{ matrix.os }}-py${{ matrix.python-version }}-ccache-
       - name: Cache Matplotlib
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         with:
           path: |
             ~/.cache/matplotlib