Modernize the library

[mourner]

A warning in Leaflet that this dev dep has some security issue has been bugging me, so I made a quick maintenance pass:

• Drop build step: switch to type: module ESM; remove Rollup/Buble and dist/.
• Drop deps: replace xregexp with native \p{ID_*} regex, minimist with node:util parseArgs, jasmine with node:test + node:assert/strict.
• ESLint 10 flat config (eslint.config.js); var → let/const, .hasOwnProperty → Object.hasOwn, misc lint fixes
• CI: GitHub Actions running npm ci + npm test on Node 24.

[mourner]

cc @IvanSanchez for your 👀

[IvanSanchez]

@mourner Running npm install; npm run test locally fails with:

node:internal/test_runner/harness:99
      throw err;
      ^

TypeError: Missing internal module 'internal/deps/brace-expansion'
    at requireBuiltin (node:internal/bootstrap/realm:429:19)
    at requireWithFallbackInDeps (node:internal/bootstrap/realm:441:10)
    at node:internal/deps/minimatch/index:7:43
    at BuiltinModule.compileForInternalLoader (node:internal/bootstrap/realm:399:7)
    at requireBuiltin (node:internal/bootstrap/realm:430:14)
    at lazyMinimatch (node:internal/fs/glob:45:17)
    at createMatcher (node:internal/fs/glob:111:15)
    at node:internal/fs/glob:298:62
    at Array.map (<anonymous>)
    at new Glob (node:internal/fs/glob:298:21)

[IvanSanchez]

Running npm install; npm run test locally fails with

Nevermind; updating nodejs from v22 to v24 fixes that issue.

[mourner]

@IvanSanchez OK fixed, should work on Node v18+ now.

[IvanSanchez]

@mourner 👍

[mourner]

@IvanSanchez nice! Can you please do a release with this in?