remove excess 'erb()' calls

[Hamms]

A couple of our pegasus rendering options are processing results as erb in addition to their actual result; this is unnecessary.

Testing Story

I checked all affected filetypes to see if any of them contained ERB syntax, and none do:

$ find . -name "*.fetch" | xargs -d '\n' grep "<%"
$ find . -name "*.redirect" | xargs -d '\n' grep "<%"
$ find . -name "*.moved" | xargs -d '\n' grep "<%"
$ find . -name "*.301" | xargs -d '\n' grep "<%"
$ find . -name "*.found" | xargs -d '\n' grep "<%"
$ find . -name "*.302" | xargs -d '\n' grep "<%"

Reviewer Checklist:

• Tests provide adequate coverage
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked