Merging PRs consecutively requires rebuild due to dist/index.js.map #271

When two PRs are merged back to back, every other open PR touching dist/ needs a manual rebase + rebuild + force-push, because dist/index.js.map conflicts (hit #260, #262, #267). Would you be open to dropping the source map from dist/? I can open a PR if so.

• Cause: the map's mappings field is one line of opaque JSON, so git can't merge two rebuilds of it. It was the only conflicting file in every case so far (re-checked on test(windows): cover sequential ifx/gfortran installs #262 and Add retry to installer downloads/installs that had none #274; dist/index.js auto-merged).
• Change: remove --source-map from the build script and delete dist/index.js.map and dist/sourcemap-register.js. verify dist needs no change.
• Cost: crash stack traces point at lines in dist/index.js instead of the source files (function names are preserved). The map can still be regenerated from any tag by building with --source-map, though note ncc's maps are already only approximate (a few lines off), since they map to transpiled source. 9 of 11 popular actions I checked (checkout, setup-node, setup-python, setup-go, ...) don't commit a map either.
• Not a full fix: dist/index.js itself can still conflict when PRs touch nearby code. If that becomes a problem, one option is to rebuild and commit dist/ from a workflow after each merge to develop, so PRs only need to carry source changes. That's a bigger change, so I'd only raise it if you want it.