Bump actions/cache from 2 to 4

Bumps [actions/cache](https://github.com/actions/cache) from 2 to 4.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v2...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] <support@github.com>

Author: dependabot[bot]

.github/workflows/coding-standard.yml

@@ -36,7 +36,7 @@ jobs:
                   extensions: pdo_sqlite
 
             - name: "Cache dependencies"
-              uses: "actions/cache@v2"
+              uses: "actions/cache@v4"
               with:
                   path: |
                       ~/.composer/cache

.github/workflows/phpstan.yml

@@ -36,7 +36,7 @@ jobs:
                   extensions: pdo_sqlite
 
             - name: "Cache dependencies"
-              uses: "actions/cache@v2"
+              uses: "actions/cache@v4"
               with:
                   path: |
                       ~/.composer/cache

.github/workflows/phpunit.yml

@@ -45,7 +45,7 @@ jobs:
                   extensions: pdo_sqlite
 
             - name: "Cache dependencies"
-              uses: "actions/cache@v2"
+              uses: "actions/cache@v4"
               with:
                   path: |
                       ~/.composer/cache

.github/workflows/psalm.yml

@@ -36,7 +36,7 @@ jobs:
                   extensions: pdo_sqlite
 
             - name: "Cache dependencies"
-              uses: "actions/cache@v2"
+              uses: "actions/cache@v4"
               with:
                   path: |
                       ~/.composer/cache