Update cache and checkout GH actions to v4

The CI/CD pipeline is breaking due to using the outdated v2 version of
the cache action. So, this change updates the workflows to use the
latest version (v4) of cache, as well as v4 of the checkout action.

Author: settermjd

.github/workflows/coding-standards.yml

@@ -16,7 +16,7 @@ jobs:
           - "8.1"
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
@@ -25,7 +25,7 @@ jobs:
           coverage: none
 
       - name: Cache dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: |
             ~/.composer/cache

.github/workflows/release-on-milestone-closed.yml

@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2"
+        uses: "actions/checkout@v4"
 
       - name: "Release"
         uses: "laminas/automatic-releases@v1"

.github/workflows/static-analysis.yml

@@ -16,7 +16,7 @@ jobs:
           - "8.2"
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
@@ -25,7 +25,7 @@ jobs:
           coverage: none
 
       - name: Cache dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: |
             ~/.composer/cache

.github/workflows/unit-tests.yml

@@ -21,7 +21,7 @@ jobs:
           - "8.2"
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
@@ -34,7 +34,7 @@ jobs:
         run: composer validate
 
       - name: Cache dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: |
             ~/.composer/cache