fix: relax npm engine enforcement in JavaScript linters

[vitormattos]

Summary

Fix the real consumer regression found in LibreCodeCoop/extract#155.

The reusable ESLint/stylelint workflows selected Node from the project's own engine but then enabled npm engine-strict. This caused npm ci to reject dependencies whose package metadata still advertises an older Node range, even though the previous workflows ran successfully.

Change

• keep selecting Node from the project's declared engine;
• keep using the npm bundled with that Node runtime;
• keep avoiding global installation of a PR-controlled npm range;
• remove global engine-strict enforcement;
• update both callers to immutable commit bf6d298f17eacdada7d2f771cad8fe29a11ec09e.

This matches the compatibility correction already made for npm-build in #30.