[Github] Add Terraform Formatting Check

This patch adds a terraform formatting check to the llvm zorg CI. This just
makes it easier to verify that patches have been formatted before landing which
prevents the need for follow up commits to reformat things later.

Reviewers: asb, Keenuts, cmtice, lnihlen

Reviewed By: cmtice

Pull Request: llvm#503

Author: boomanaiden154

.github/workflows/tf-formatting.yml

@@ -0,0 +1,29 @@
+name: Terraform Formatting Check
+
+permissions:
+  contents: read
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  check_formatting:
+    name: Check Formatting
+    if: github.repository_owner == 'llvm'
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install Dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y curl
+        curl https://releases.hashicorp.com/terraform/1.12.2/terraform_1.12.2_linux_amd64.zip > /tmp/tf.zip
+        cd /tmp
+        unzip /tmp/tf.zip
+        cp terraform /usr/local/bin/terraform
+    - name: Check Formatting
+      run: |
+        terraform fmt -recursive -check .