internal/golangorgx: remove gopls re-vendoring script

This script was added in early 2024 when Paul did the initial imports
of the gopls codebase into internal/golangorgx.

At this point, we are moving towards deleting or rewriting most of
these gopls files, and we will soon stop having internal/golangorgx
altogether. Most importantly, this script is no longer needed.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I8e053ac27664c2bbb49ba3e2b5a1e1cab01f6134
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1218308
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Matthew Sackman <[email protected]>

Author: mvdan