ci: Use ubuntu latest for some ci jobs (#1939)

Ubuntu 20.04 images will be deprecated soon:
https://github.com/actions/runner-images/issues/11101
Switch to the latest Ubuntu everywhere we use Github's image.

.github/workflows/build.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   check_format:
     name: Check format
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     container:
       image: rippleci/clio_ci:latest
     steps:
@@ -26,7 +26,7 @@ jobs:
  
   check_docs:
     name: Check documentation
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     container:
       image: rippleci/clio_ci:latest
     steps:

.github/workflows/build_clio_docker_image.yml

@@ -40,7 +40,7 @@ on:
 jobs:
   build_and_publish_image:
     name: Build and publish image
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
 

.github/workflows/check_libxrpl.yml

@@ -71,7 +71,7 @@ jobs:
     name: Create an issue on failure
     needs: [build, run_tests]
     if: ${{ always() && contains(needs.*.result, 'failure') }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     permissions:
       contents: write
       issues: write

.github/workflows/check_pr_title.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   check_title:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     # permissions:
     #   pull-requests: write
     steps:

.github/workflows/clang-tidy_on_fix_merged.yml

@@ -6,7 +6,7 @@ on:
 
 jobs:
   restart_clang_tidy:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
 
     permissions:
       actions: write

.github/workflows/docs.yml

@@ -18,7 +18,7 @@ jobs:
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     continue-on-error: true
     container:
       image: rippleci/clio_ci:latest

.github/workflows/nightly.yml

@@ -102,7 +102,7 @@ jobs:
   nightly_release:
     if: ${{ github.event_name != 'pull_request' }}
     needs: run_tests
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     env:
       GH_REPO: ${{ github.repository }}
       GH_TOKEN: ${{ github.token }}
@@ -158,7 +158,7 @@ jobs:
   create_issue_on_failure:
     needs: [build, run_tests, nightly_release, build_and_publish_docker_image]
     if: ${{ always() && contains(needs.*.result, 'failure') && github.event_name != 'pull_request' }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     permissions:
       contents: write
       issues: write

.github/workflows/upload_coverage_report.yml

@@ -9,7 +9,7 @@ on:
 jobs:
   upload_report:
     name: Upload report
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with: