Apply Drupal Rector to Islandora.

[rosiel]

GitHub Issue: part of Islandora/documentation#2235

• Other Relevant Links (Google Groups discussion, related pull requests,
  Release pull requests, etc.)

What does this Pull Request do?

Accepts suggestions made by Drupal Rector to fix deprecated code. This will be necessary before Drupal 10, but will also work with Drupal 9.

What's new?

Numerous rules applied.

• Does this change add any new dependencies? no
• Does this change require any other modifications to be made to the repository
  (i.e. Regeneration activity, etc.)? no
• Could this change impact execution of existing code? yes, but it shouldn't!

How should this be tested?

• Run the Islandora tests (in CI should do?)

Documentation Status

• Does this change existing behaviour that's currently documented? hope not
• Does this change require new pages or sections of documentation? no
• Who does this need to be documented for? no
• Associated documentation pull request(s): ___ or documentation issue ___

Additional Notes:

Any additional information that you think would be helpful when reviewing this
PR.

Interested parties

Tag (@ mention) interested parties or, if unsure, @Islandora/committers

[adam-vessey]

Giving a quick look over, seems to be some funky things going on...

[alxp]

I ran PHPUnit on this branch. It shows no new failing tests or errors on a D9 site, so this PR can be merged as is.

However it did show quite a few deprecation notices for code that will be removed in Drupal 10 that Rector may not have caught.

We can either do those changes in this ticket, or make a new one for those, either is fine with me.

phpunit_output_islandora-rosiel-drupal10.txt

[rosiel]

(edit to say) I'll take a look at what can be fixed from that!