Show count of preserved theses in publication results email

[jazairi]

Why these changes are being introduced:

The publication results email shows the full array of preserved
thesis. It should show the total count instead.

Relevant ticket(s):

N/A.

How this addresses that need:

This changes the publication results email view to render the count
of preserved theses.

Side effects of this change:

None.

Developer

• All new ENV is documented in README
• All new ENV has been added to Heroku Pipeline, Staging and Prod
• ANDI or Wave has been run in accordance to
  our guide and
  all issues introduced by these changes have been resolved or opened as new
  issues (link to those issues in the Pull Request details above)
• Stakeholder approval has been confirmed (or is not needed)

Code Reviewer

• The commit message is clear and follows our guidelines
  (not just this pull request message)
• There are appropriate tests covering any new functionality
• The documentation has been updated or is unnecessary
• The changes have been verified
• New dependencies are appropriate or there were no changes

Requires database migrations?

NO

Includes new or updated dependencies?

NO

[coveralls]

Coverage remained the same at 97.047% when pulling 175a8f0 on fix-pub-results-email into a069d54 on main.