[performance] handle emoji refreshes asynchronously when fetched as part of account|status dereferences (#4486)

# Description

Updates our dereferencer emoji handling to work asynchronously when going through the route of account or status dereferencing.

closes https://codeberg.org/superseriousbusiness/gotosocial/issues/4485

## Checklist

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] 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.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4486
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

internal/processing/admin/emoji.go

@@ -293,6 +293,7 @@ func (p *Processor) emojiUpdateCopy(
 	// Ensure target emoji is locally cached.
 	target, err := p.federator.RecacheEmoji(ctx,
 		target,
+		false,
 	)
 	if err != nil {
 		err := gtserror.Newf("error recaching emoji %s: %w", target.ImageRemoteURL, err)