Update tools to use Unity 2021

[a-maurice]

Description

Provide details of the change, and generalize the change in the PR title above.

Update the build and test tools to use Unity 2021.3.43f1. Update the testapps to use that version as well. Update to use Java 11 instead of Java 8, needed by the latest version of C++ because of gradle changes. Update the XCode capabilities to use the ProjectCapabilityManager instead of copying entitlement files and doing it manually.

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Testing

Describe how you've tested these changes.

Various GHA runs

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Type of Change

Place an x the applicable box:

• Bug fix. Add the issue # below if applicable.
• New feature. A non-breaking change which adds functionality.
• Other, such as a build process or documentation change.

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[jonsimantov]

Actually relatively straightforward, except the capabilities stuff, which is much nicer now than it was before.