Remove Mockito dependency from project

[jamesonwilliams]

Contributor checklist

• I am following the Code Style Guidelines
• I have tested my contribution on these devices:

• MacBook Pro

• My contribution is fully baked and ready to be merged as is
• I ensure that all the open issues my contribution fixes are mentioned in the commit message of my first commit using the Fixes #1234 syntax

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Description

This is the final pull request in a series, to move off of Mockito. Prior work went in via these commits:

• Migrate last batch of mockito tests #13835
• Migrates a batch of tests from Mockito -> MockK #13832
• Convert the last batch of Mockito/Java tests to Kotlin/MockK #13829
• Convert another batch of Java unit tests to Kotlin #13825
• Kotlin-ize some more tests #13813
• Convert some Java tests to Kotlin #13792

After the current PR, mockito can't be found in the project:

$ rg -i mockito | wc -l 
       0

Testing

This still passes:

./gradlew qa

[greyson-signal]

Woohoo! Thank you! Heads up that this will go out in 7.29, which likely won't be until after the holidays :)