I discovered this[0] "allowlist" approach for Go a while ago:

  # Ignore everything
  \*
  
  # But not these files...
  !/.gitignore
  !*.go
  !go.sum
  !go.mod
  !README.md
  !LICENSE
  
  # ...even if they are in subdirectories
  !*/

[0] https://github.com/github/gitignore/blob/main/community/Gola...