Use ubuntu-latest for all ci jobs

ubuntu 20.04 is now deprecated:
actions/runner-images#11101

Author: rushilmehra

.github/workflows/ci.yml

@@ -242,7 +242,7 @@ jobs:
 
   test-fips:
     name: Test FIPS integration
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
       with:
@@ -342,7 +342,7 @@ jobs:
 
   test-features:
     name: Test features
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
       with: