build.yaml: Replace dead ubuntu-18.04 by current ubuntu-24.04

Package subversion turned out tonot be installed
with ubuntu-24.04.

Author: hartwork

.github/workflows/build.yaml

@@ -26,10 +26,10 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          - runs-on: ubuntu-24.04
+            qt: qt5-qmake
           - runs-on: ubuntu-22.04
             qt: qt5-qmake
-          - runs-on: ubuntu-18.04
-            qt: qt5-default
 
     name: Build (Linux, ${{ matrix.runs-on }})
     runs-on: ${{ matrix.runs-on }}
@@ -43,7 +43,8 @@ jobs:
             libapr1-dev \
             libsvn-dev \
             ${{ matrix.qt }} \
-            qtbase5-dev
+            qtbase5-dev \
+            subversion
 
       - name: 'Checkout Git branch'
         uses: actions/checkout@v3