ci: remove environment scoping so repo-level secrets are used

The migrate and deploy jobs referenced environment: production, which
requires secrets to be configured per-environment in GitHub. Removing
the environment key so they use repository-level secrets instead.

Author: richiemcilroy

.github/workflows/deploy-api.yml

@@ -60,7 +60,6 @@ jobs:
     needs: check
     runs-on: ubuntu-latest
     timeout-minutes: 5
-    environment: ${{ inputs.stage || 'production' }}
     steps:
       - uses: actions/checkout@v4
 
@@ -80,7 +79,6 @@ jobs:
     needs: migrate
     runs-on: ubuntu-latest
     timeout-minutes: 15
-    environment: ${{ inputs.stage || 'production' }}
     steps:
       - uses: actions/checkout@v4