Checkout code for release workflow

The code is needed to find/execute the `release.sh` script.

Also removed some duplicate/redundant workflow properies.

Squashed commit of the following:

commit 504714e87b3dbe82503bca38caa52f7c7343f5c8
Author: Paul Colby <[email protected]>
Date:   Mon Mar 10 14:05:26 2025 +1100

    Restore build jobs

commit fde2b9f
Author: Paul Colby <[email protected]>
Date:   Mon Mar 10 13:31:20 2025 +1100

    Checkout the code so we have the release.sh script available

commit 677ca48
Author: Paul Colby <[email protected]>
Date:   Mon Mar 10 12:47:35 2025 +1100

    Remove duplicate env properties

Author: pcolby

.github/workflows/release.yaml

@@ -4,21 +4,18 @@ on:
   workflow_dispatch:
     inputs:
       tag:
-        description: Tag to release
+        description: Existing tag to draft a release for
         required: true
         type: string
 
 permissions:
   contents: write
 
-env:
-  GH_REPO: ${{ github.repository }}
-  GH_TOKEN: ${{ github.token }}
-
 jobs:
   release:
     runs-on: ubuntu-24.04
     steps:
+      - uses: actions/checkout@v4
       - name: Create draft release
         run: .github/workflows/release.sh "${TAG_NAME}"
         env: