upgrading Actions image to supported version of ubuntu

Author: andrus

.github/workflows/maven.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     name: JDK ${{ matrix.java }}
     strategy:
       matrix:
@@ -28,7 +28,7 @@ jobs:
 
   deploy:
     needs: build
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
 
     steps:
       - name: Checkout...