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] <support@github.com>

.github/workflows/coverage.yml

@@ -51,7 +51,7 @@ jobs:
           curl -LO https://github.com/protocolbuffers/protobuf/releases/download/v21.4/protoc-21.4-linux-x86_64.zip
           unzip protoc-21.4-linux-x86_64.zip
       - name: Cache Cargo
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: /home/runner/.cargo
           key: cargo-coverage-cache3-

.github/workflows/integration.yml

@@ -119,12 +119,12 @@ jobs:
           rustup default ${{ matrix.rust }}
           rustup component add rustfmt clippy
       - name: Cache Cargo
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: /home/runner/.cargo
           key: cargo-maturin-cache-
       - name: Cache Rust dependencies
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: /home/runner/target
           # this key is not equal because maturin uses different compilation flags.