Add linting for jank-build.bb files - #21

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Cannot verify integrity of 'd09a6a346b8729bc11d83609179f92ab18a946ca79abc25307ca6fab0795d84a--jank_0.1-1_aarch64.tar.gz'. No checksum was provided. For your reference, the checksum is: sha256 "efc1b4b256a576a32d8f823e0126fdbaad04733ff9c3fe378556c77e16807480"