Drop Ubuntu Focal v20.04 from the CI roster

.github/workflows/ci.yml

@@ -302,11 +302,6 @@ jobs:
       matrix:
         include:
           # Use `-fno-var-tracking-assignments` to reduce amount of produced debug information. This is necessary due to 100MiB limit of GitHub / openrct2.org API.
-          # For focal the debug information still takes too much space, so reduce amount of debug info to minimum using `-g1` (`-g` means `-g2`), which is enough for backtraces only.
-          - platform: x86_64
-            distro: focal
-            image: openrct2/openrct2-build:14-focal
-            build_flags: -DCMAKE_POSITION_INDEPENDENT_CODE=on -DCMAKE_CXX_FLAGS="-g1 -gz" -DWITH_TESTS=off
           - platform: x86_64
             distro: jammy
             image: openrct2/openrct2-build:14-jammy
@@ -316,9 +311,9 @@ jobs:
             image: openrct2/openrct2-build:14-bullseye
             build_flags: -DCMAKE_POSITION_INDEPENDENT_CODE=on -DCMAKE_CXX_FLAGS="-g -gz -fno-var-tracking-assignments" -DWITH_TESTS=off
           - platform: i686
-            distro: focal
-            image: openrct2/openrct2-build:14-focal32
-            build_flags: -DFORCE32=ON -DENABLE_SCRIPTING=OFF -DCMAKE_CXX_FLAGS="-m32 -g1 -gz" -DWITH_TESTS=off
+            distro: jammy
+            image: openrct2/openrct2-build:14-jammy32
+            build_flags: -DFORCE32=ON -DENABLE_SCRIPTING=OFF -DCMAKE_CXX_FLAGS="-m32 -g -gz" -DWITH_TESTS=off
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -356,7 +351,7 @@ jobs:
     name: Linux (x86_64, AppImage)
     runs-on: ubuntu-latest
     needs: check-code-formatting
-    container: openrct2/openrct2-build:14-focal
+    container: openrct2/openrct2-build:14-jammy
     steps:
       - name: Checkout
         uses: actions/checkout@v4