refactor: pin chromium test to same Ubuntu as before

See last passing job in old repo: https://github.com/angular/material.angular.io/actions/runs/12390917032/job/34586949768

Author: alexeagle

.github/workflows/ci.material-aio.yml

@@ -62,7 +62,7 @@ jobs:
           retention-days: 14
 
   lighthouse:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04 # Note, fails on Ubuntu 24.04, see https://github.com/actions/runner-images/issues/10636
     steps:
       - name: Initialize environment
         uses: angular/dev-infra/github-actions/npm/checkout-and-setup-node@359350bbc10aab1bac85d0eec61a53377078ab82

.github/workflows/pr.material-aio.yml

@@ -60,7 +60,7 @@ jobs:
           retention-days: 14
 
   lighthouse:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04 # Note, fails on Ubuntu 24.04, see https://github.com/actions/runner-images/issues/10636
     steps:
       - name: Initialize environment
         uses: angular/dev-infra/github-actions/npm/checkout-and-setup-node@359350bbc10aab1bac85d0eec61a53377078ab82