Don't use ubicloud everywhere

Author: DavyLandman

.github/workflows/pr-builder.yml

@@ -11,7 +11,7 @@ jobs:
 
   website-pr:
     name: Sanity check the Rascal website
-    runs-on: ubicloud-standard-2
+    runs-on: ubuntu-latest
     needs: prepare-website
     steps:
       # Download prepared sources from base

.github/workflows/website-builder.yml

@@ -11,7 +11,7 @@ jobs:
 
   website:
     name: Deploy the Rascal website
-    runs-on: ubicloud-standard-2
+    runs-on: ubuntu-latest
     needs: prepare-website
     steps:
       # Download prepared sources from base