[ci] Add /pregen to pregenerate files (#6786)

.github/workflows/comment-command.yml

@@ -56,3 +56,49 @@ jobs:
           # Commit
           git commit -am "Formatting fixes"
           git push
+
+  pregen:
+    if: github.event.issue.pull_request && startsWith(github.event.comment.body, '/pregen')
+    runs-on: ubuntu-22.04
+    steps:
+      - name: React Rocket
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const {owner, repo} = context.issue
+            github.rest.reactions.createForIssueComment({
+              owner,
+              repo,
+              comment_id: context.payload.comment.id,
+              content: "rocket",
+            });
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          token: ${{ secrets.COMMENT_COMMAND_PAT_TOKEN }}
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.9
+      - name: Install jinja
+        run: python -m pip install jinja2
+      - name: Install protobuf dependencies
+        run: sudo apt-get update && sudo apt-get install -y protobuf-compiler && wget https://github.com/HebiRobotics/QuickBuffers/releases/download/1.3.3/protoc-gen-quickbuf-1.3.3-linux-x86_64.exe && chmod +x protoc-gen-quickbuf-1.3.3-linux-x86_64.exe
+      - name: Run hal
+        run: ./hal/generate_usage_reporting.py
+      - name: Run ntcore
+        run: ./ntcore/generate_topics.py
+      - name: Run wpimath
+        run: ./wpimath/generate_numbers.py && ./wpimath/generate_quickbuf.py --quickbuf_plugin=protoc-gen-quickbuf-1.3.3-linux-x86_64.exe
+      - name: Run HIDs
+        run: ./wpilibj/generate_hids.py && ./wpilibc/generate_hids.py && ./wpilibNewCommands/generate_hids.py
+      - name: Run PWM Controllers
+        run: ./wpilibj/generate_pwm_motor_controllers.py && ./wpilibc/generate_pwm_motor_controllers.py
+      - name: Commit
+        run: |
+          # Set credentials
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          # Commit
+          git commit -am "Regenerate pregenerated files"
+          git push