Ensure tags fields are assigned to tpl for email form test

[eileenmcnaughton]

Re-instate #22614

@demeritcowboy I looked at ^^ and you reported that it broke something - but I realised I couldn't replicate the thing you said was broken - you said "but running it this breaks tags for attachments (the field doesn't appear)." - - I can't figure out how to make the tag field appear for attachments....

[civibot]

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[demeritcowboy]

On dmaster.demo right now: https://dmaster.demo.civicrm.org/civicrm/activity?reset=1&action=add&context=standalone

Expand attachments section.

[eileenmcnaughton]

@demeritcowboy OK - I think I figured it out - I added some additional cleanup

[demeritcowboy]

jenkins retest this please

[demeritcowboy]

There's something wrong with how attachment tags get stored, but it doesn't seem to be from this PR.
https://lab.civicrm.org/dev/core/-/issues/3185

[eileenmcnaughton]

Thanks @demeritcowboy