The following file paths/patterns are not interesting in a .nupkg archive and can be ignores safely.

rels/.rels
to/[Content_Types].xml
to/package/services/metadata*
to/.signature.p7s
*.png
*.runtimeconfig.json
*.dll.config
*.exe.config
*.shasum

These are mostly nuget ecosystem specific ignorables, with configurations, metadata and checksums.

The following could also be ignored potentitally:
.editorconfig
.props
.targets