Revert "CI: removed ubuntu 20.04, added ubuntu 24.04"

This reverts commit d15eec70566b86f0c3ab1a940ca6b562701fdb9c.

Ubuntu 24.04 image is not yet public...

.github/workflows/build.yml

@@ -20,8 +20,8 @@ jobs:
           build_deb: false
           defines: ""
 
-        - name: "ubuntu_22.04"
-          os: ubuntu-22.04
+        - name: "ubuntu_20.04"
+          os: ubuntu-20.04
           generator: "Unix Makefiles"
           arch: ""
           target: traintastic-client
@@ -30,8 +30,8 @@ jobs:
           build_deb: true
           defines: ""
 
-        - name: "ubuntu_24.04"
-          os: ubuntu-24.04
+        - name: "ubuntu_22.04"
+          os: ubuntu-22.04
           generator: "Unix Makefiles"
           arch: ""
           target: traintastic-client
@@ -197,6 +197,18 @@ jobs:
           defines: ""
           ccov: false
 
+        - name: "ubuntu_20.04"
+          os: ubuntu-20.04
+          generator: "Unix Makefiles"
+          arch: ""
+          toolset: ""
+          target: all
+          jobs: 4
+          build_type: Release
+          build_deb: true
+          defines: "-DENABLE_CLANG_TIDY=ON -DINSTALL_SYSTEMD_SERVICE=ON"
+          ccov: false
+
         - name: "ubuntu_22.04"
           os: ubuntu-22.04
           generator: "Unix Makefiles"
@@ -209,20 +221,8 @@ jobs:
           defines: "-DENABLE_CLANG_TIDY=ON -DINSTALL_SYSTEMD_SERVICE=ON"
           ccov: false
 
-        - name: "ubuntu_24.04"
-          os: ubuntu-24.04
-          generator: "Unix Makefiles"
-          arch: ""
-          toolset: ""
-          target: all
-          jobs: 4
-          build_type: Release
-          build_deb: true
-          defines: "-DENABLE_CLANG_TIDY=ON -DINSTALL_SYSTEMD_SERVICE=ON"
-          ccov: false
-
-        - name: "ubuntu_latest (debug+ccov)"
-          os: ubuntu-latest
+        - name: "ubuntu_20.04 (debug+ccov)"
+          os: ubuntu-20.04
           generator: "Unix Makefiles"
           arch: ""
           toolset: ""
@@ -397,12 +397,12 @@ jobs:
       fail-fast: false
       matrix:
         config:
-        - name: "ubuntu_22.04"
-          os: ubuntu-22.04
+        - name: "ubuntu_20.04"
+          os: ubuntu-20.04
           defines: ""
 
-        - name: "ubuntu_24.04"
-          os: ubuntu-24.04
+        - name: "ubuntu_22.04"
+          os: ubuntu-22.04
           defines: ""
 
         - name: "raspberrypios_10"
@@ -473,7 +473,7 @@ jobs:
 
   build-manual:
     name: manual
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
 
     steps:
     - uses: FranzDiebold/github-env-vars-action@v2
@@ -587,7 +587,7 @@ jobs:
   deploy:
     name: Deploy to website
     if: ${{ github.event_name == 'push' }}
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     needs: [package-innosetup, build-server, build-client, build-data, build-manual, build-manual-lua]
 
     steps: