fix(ci): Run check-flake on Pull Requests and add Andi as a reviewer for automated flake.lock updates

Author: mrjones2014

.github/workflows/check-flake.yml

@@ -1,6 +1,9 @@
 name: Check Nix flake
 on:
-  pull_request:
+  pull_request_target:
+    paths:
+      - '*.nix'
+      - flake.lock
   push:
     branches:
       - main

.github/workflows/update-flake-dependencies.yml

@@ -33,5 +33,5 @@ jobs:
               --field content=@<(base64 -i $FILE_TO_COMMIT) \
               --field branch="$COMMIT_BRANCH" \
               --field sha="$(git rev-parse $COMMIT_BRANCH:$FILE_TO_COMMIT)"
-            gh pr create --title "[automation]: Update Flake dependencies" --body "This is an automated PR to update \`flake.lock\`" --reviewer mrjones2014 --base main --head $COMMIT_BRANCH
+            gh pr create --title "[automation]: Update Flake dependencies" --body "This is an automated PR to update \`flake.lock\`" --reviewer mrjones2014 --reviewer AndyTitu --base main --head $COMMIT_BRANCH
           fi