Export LSTK_CONFIG_FILE via GITHUB_ENV (runner context is invalid in job env)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: silv-io

.github/workflows/release.yml

@@ -24,7 +24,6 @@ jobs:
       id-token: write
     env:
       RELEASE_VERSION: ${{ github.event_name == 'workflow_dispatch' && inputs.version || github.event.client_payload.version}}
-      LSTK_CONFIG_FILE: ${{ runner.temp }}/lstk-config.toml
 
     steps:
     - name: "Pull Image (localstack/localstack-pro:${{ env.RELEASE_VERSION }})"
@@ -72,12 +71,13 @@ jobs:
       # The config pins the emulator image to the release version. It lives outside
       # the workspace so the "Check Uncommitted Changes" step stays clean.
       run: |
-        cat > "${LSTK_CONFIG_FILE}" <<EOF
+        cat > "${RUNNER_TEMP}/lstk-config.toml" <<EOF
         [[containers]]
         type = "aws"
         tag = "${RELEASE_VERSION}"
         port = "4566"
         EOF
+        echo "LSTK_CONFIG_FILE=${RUNNER_TEMP}/lstk-config.toml" >> "$GITHUB_ENV"
 
     - name: "Start Localstack"
       env: