Do Not Run Some Workflows on Dependabot's PRs

Issue gh-13873

(cherry picked from commit 3aae03b1b2414c847ec61bb430ba4445c1bcadf5)

.github/workflows/continuous-integration-workflow.yml

@@ -1,6 +1,9 @@
 name: CI
 
 on:
+  pull_request:
+    branches-ignore:
+      - "dependabot/**"
   push:
     branches-ignore:
       - "dependabot/**"

.github/workflows/deploy-docs.yml

@@ -1,7 +1,12 @@
 name: Deploy Docs
 on:
+  pull_request:
+    branches-ignore:
+      - "dependabot/**"
   push:
-    branches-ignore: [ "gh-pages", "dependabot/**" ]
+    branches-ignore:
+      - "gh-pages"
+      - "dependabot/**"
     tags: '**'
   repository_dispatch:
     types: request-build-reference # legacy