Use ubuntu-latest for actions

Author: TomHAnderson

.github/workflows/continuous-integration.yml

@@ -13,7 +13,7 @@ on:
 jobs:
   phpunit:
     name: "PHPUnit"
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-latest"
 
     strategy:
       fail-fast: false
@@ -47,7 +47,7 @@ jobs:
         with:
           dependency-versions: "${{ matrix.dependencies }}"
           composer-options: "--prefer-dist"
-          
+
       - name: "Show Composer packages"
         run: "composer show"
 
@@ -62,7 +62,7 @@ jobs:
 
   upload_coverage:
     name: "Upload coverage to Codecov"
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-latest"
     needs:
       - "phpunit"
 

.github/workflows/static-analysis.yml

@@ -13,7 +13,7 @@ on:
 jobs:
   psalm:
     name: "Static Analysis"
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-latest"
 
     steps:
       - uses: shivammathur/setup-php@v2