The map file incorrectly contains the `dist/` prefix in & `file` `sources` fields

[mgol]

Description

The dist/jquery.min.js.map file generated by Terser contains two fields with incorrect values:

"file":"dist/jquery.min.map",
"sources":["dist/jquery.js"]

The proper values are:

"file":"jquery.min.js",
"sources":["jquery.js"]

and that's what we have on the 3.x-stable line with UglifyJS.

Note that not only the dist/ prefix should go away but also the Terser's source map incorrectly points to itself in the file property.

We need to fix it before the final 4.0.0 release.

Link to test case

[mgol]

Switching to SWC and fixing this as well in #5286.