Merge pull request #655 from crazy-max/rm-ubuntu-20

ci: update ubuntu runners to latest

.github/workflows/validate.yml

@@ -15,7 +15,7 @@ on:
 
 jobs:
   prepare:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     outputs:
       targets: ${{ steps.generate.outputs.targets }}
     steps:

.github/workflows/virtual-env.yml

@@ -23,7 +23,6 @@ jobs:
           - ubuntu-latest
           - ubuntu-24.04
           - ubuntu-22.04
-          - ubuntu-20.04
           - ubuntu-24.04-arm
           - ubuntu-22.04-arm
     steps: