[chore] add back exif-terminator and use only for jpeg,png,webp

[NyaaaWhatsUpDoc]

Description

So it turns out that ffmpeg -map_metadata -1 can indeed clean all metadata, BUT if you're not performing any encoding then the most metadata it can clean is at the global level. Any stream metadata (which is often the case with EXIF) cannot be removed since it's not stepping through the stream data.

This PR adds back exif-terminator to be used exclusively for "jpeg", "png", "webp". All other filetypes fall back to best-effort exif data removal using ffmpeg.

• waiting on merge + release of: https://codeberg.org/superseriousbusiness/exif-terminator/pulls/11

Checklist

• I/we have read the GoToSocial contribution guidelines.
• I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
• I/we have not leveraged AI to create the proposed changes.
• I/we have performed a self-review of added code.
• I/we have written code that is legible and maintainable by others.
• I/we have commented the added code, particularly in hard-to-understand areas.
• I/we have made any necessary changes to documentation.
• I/we have added tests that cover new code.
• I/we have run tests and they pass locally with the changes.
• I/we have run go fmt ./... and golangci-lint run.

[tsmethurst]

Took the liberty of fixing the test failure :)

[NyaaaWhatsUpDoc]

@tsmethurst you're an angel :O

[tsmethurst]

i can be ur angle... or ur deville

[NyaaaWhatsUpDoc]

https://www.youtube.com/watch?v=oz4MDhBjsFQ