test: fix stale e2e scenario assertions from #138 and #140

[joshua-temple]

Problem

Three e2e scenario assertions went stale because generator output legitimately changed in #140 and #138. The generator behavior is correct; the assertions lagged behind.

• 12-inline-run-callback.yaml and 10-inline-job-attributes.yaml asserted uses: ./build.yaml, but fix: normalize local callback workflow paths to .github/workflows #140 made the generator emit the fully-qualified uses: ./.github/workflows/build.yaml.
• orchestrate/env-gates.yaml asserted a job-level environment: key on a reusable-workflow (uses:) deploy. Per Generator emits 'environment:' on reusable-workflow (uses:) deploy jobs, which GitHub rejects #137/fix: omit job-level environment on reusable-workflow deploy jobs #138 the generator now correctly omits the job-level key on a uses: caller job (GitHub Actions forbids it there).

Fix (test-only)

• Updated the two uses: assertions to the fully-qualified path.
• Converted the env-gates cdk deploy to an inline run: deploy, the job kind on which a job-level environment: key is actually valid, so the env-gate feature is genuinely exercised. The asserted 4-space, newline-anchored environment: ${{ github.event.inputs.environment || 'dev' }} now matches real output.

Verification

All new assertion strings were proven against real generator output (generate-workflow --orchestrate-only):

• S12/S10: uses: ./.github/workflows/build.yaml present verbatim.
• env-gates: environment: ${{ github.event.inputs.environment || 'dev' }} present at the 4-space job level.

go build ./... and cd e2e && go vet ./... are clean. The full act-based e2e suite was not run because local Docker is down.