fixup! Stop running pull request workflow on main

Instead of running the checks on `main`, I've opted to just rebase the current branch onto `main` as part of the workflow process so that I don't need to run checks twice, which starves CI resources and doubles the minutes I'd run tests on Firebase Test Lab

.forgejo/workflows/pull_request.yml

@@ -2,8 +2,6 @@ name: Build & Test
 
 on:
   pull_request:
-  push:
-    branches: [ main ]
 
 jobs:
   validate:
@@ -11,6 +9,7 @@ jobs:
     name: Validate
     steps:
     - uses: actions/checkout@v4
+    - run: git rebase origin/main
     - name: set up JDK
       uses: https://git.wbrawner.com/actions/setup-java@v4
       with:
@@ -25,6 +24,7 @@ jobs:
     - validate
     steps:
       - uses: actions/checkout@v4
+      - run: git rebase origin/main
       - name: set up JDK
         uses: https://git.wbrawner.com/actions/setup-java@v4
         with:
@@ -50,6 +50,7 @@ jobs:
       - validate
     steps:
       - uses: actions/checkout@v4
+      - run: git rebase origin/main
       - name: set up JDK
         uses: https://git.wbrawner.com/actions/setup-java@v4
         with: