Bump actions/cache from 3 to 4 (open-telemetry#578)

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-version: '4'
  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>
Co-authored-by: Tom Tan <[email protected]>

Author: dependabot[bot]

.github/workflows/prometheus.yml

@@ -25,7 +25,7 @@ jobs:
         with:
           path: "otel_cpp_contrib"
       - name: Mount Bazel Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         env:
           cache-name: bazel_cache
         with:
@@ -45,7 +45,7 @@ jobs:
         with:
           path: "otel_cpp_contrib"
       - name: Mount Bazel Cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         env:
           cache-name: bazel_cache
         with:

.github/workflows/webserver.yml

@@ -28,7 +28,7 @@ jobs:
         with:
           install: true
       - name: cache docker layers
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: /tmp/buildx-cache/
           key: apache-ubuntu-20.04-${{ github.sha }}
@@ -72,7 +72,7 @@ jobs:
         with:
           install: true
       # - name: cache docker layers
-      #   uses: actions/cache@v3
+      #   uses: actions/cache@v4
       #   with:
       #     path: /tmp/buildx-cache/
       #     key: apache-centos7-${{ github.sha }}
@@ -141,7 +141,7 @@ jobs:
         with:
           install: true
       # - name: cache docker layers
-      #   uses: actions/cache@v3
+      #   uses: actions/cache@v4
       #   with:
       #     path: /tmp/buildx-cache/
       #     key: apache-almalinux8-${{ github.sha }}