ci: doc: use Ubuntu 22.04

Use the latest Ubuntu image. There's no special reason for this change
other than staying up-to-date.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

.github/workflows/doc-build.yml

@@ -35,7 +35,7 @@ env:
 jobs:
   doc-build-html:
     name: "Documentation Build (HTML)"
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     timeout-minutes: 45
     concurrency:
       group: doc-build-html-${{ github.ref }}

.github/workflows/doc-publish-pr.yml

@@ -13,7 +13,7 @@ on:
 jobs:
   doc-publish:
     name: Publish Documentation
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     if: |
       github.event.workflow_run.event == 'pull_request' &&
       github.event.workflow_run.conclusion == 'success' &&

.github/workflows/doc-publish.yml

@@ -16,7 +16,7 @@ on:
 jobs:
   doc-publish:
     name: Publish Documentation
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     if: |
       github.event.workflow_run.event != 'pull_request' &&
       github.event.workflow_run.conclusion == 'success' &&