Update ubuntu-20.04 runners to latest in GitHub Actions pipelines

Fixes #714

Author: atextor

.github/workflows/pull-request-check.yml

@@ -12,15 +12,15 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        os: [windows-latest, ubuntu-20.04, macos-13]
+        os: [windows-latest, ubuntu-latest, macos-13]
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
         with:
           submodules: recursive
 
       - name: Check code style
-        if: matrix.os == 'ubuntu-20.04'
+        if: matrix.os == 'ubuntu-latest'
         uses: dbelyaev/action-checkstyle@e89baf0f8b488b946345b7de8e975be1e3606387 # v1.5.6
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
@@ -59,7 +59,7 @@ jobs:
           disk-root: "C:"
 
       - name: Set Swap Space (Linux)
-        if: matrix.os == 'ubuntu-20.04'
+        if: matrix.os == 'ubuntu-latest'
         uses: pierotofy/set-swap-space@49819abfb41bd9b44fb781159c033dba90353a7c # master
         with:
           swap-size-gb: 12
@@ -120,14 +120,14 @@ jobs:
           overwrite-settings: false
 
       - name: Test executable jar on Temurin
-        if: matrix.os == 'ubuntu-20.04'
+        if: matrix.os == 'ubuntu-latest'
         run: |
           cd tools/samm-cli
           mvn -B -Denforcer.skip -Dskip.maven.surefire failsafe:integration-test -Dmaven.wagon.httpconnectionManager.ttlSeconds=60
 
       - name: Upload executable jar
         # We only need one OS job to upload the jar
-        if: matrix.os == 'ubuntu-20.04'
+        if: matrix.os == 'ubuntu-latest'
         uses: actions/upload-artifact@v4
         with:
           name: samm-cli-jar
@@ -145,7 +145,7 @@ jobs:
             tools/samm-cli/target/lib/
 
       - name: Upload binary (Linux)
-        if: matrix.os == 'ubuntu-20.04'
+        if: matrix.os == 'ubuntu-latest'
         uses: actions/upload-artifact@v4
         with:
           name: samm-cli-binary-${{ matrix.os }}

.github/workflows/release-workflow.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   check-preconditions:
     name: Check preconditions
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -48,7 +48,7 @@ jobs:
   build-linux:
     name: Linux build
     needs: [check-preconditions]
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4