[bugfix] process account delete synchronously to prevent OOM (#4260)

# Description

- updates account delete processing to handle side-effects synchronously to prevent OOM
- updates account delete processing to check more often if account.IsLocal() for certain deletes / side-effects
- ensures that mutes get removed from database on delete

## 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.
- [x] 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/4260
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

internal/processing/workers/fromclientapi.go

@@ -1093,11 +1093,13 @@ func (p *clientAPI) DeleteAccountOrUser(ctx context.Context, cMsg *messages.From
 		p.state.Caches.Timelines.List.Delete(listID)
 	}
 
+	// Federate out a delete activity targeting account to remote servers.
 	if err := p.federate.DeleteAccount(ctx, cMsg.Target); err != nil {
 		log.Errorf(ctx, "error federating account delete: %v", err)
 	}
 
-	if err := p.account.Delete(ctx, cMsg.Target, originID); err != nil {
+	// And finally, perform the actual account deletion synchronously.
+	if err := p.account.Delete(ctx, account, originID); err != nil {
 		log.Errorf(ctx, "error deleting account: %v", err)
 	}