[rollup-plugin-copy][rollup-plugin-import-meta-assets]: type declarations defined in `exports` are not present in the published package

[nicklemmon]

For both @web/rollup-plugin-copy and @web/rollup-plugin-import-meta-assets the index.d.ts file is not present despite being referenced in the package exports["."].types field.

• @web/rollup-plugin-copy package contents
• @web/rollup-plugin-import-meta-assets package contents

This may be impacting other packages in this repo as well.