build!: drop node 10, update typescript to 4.6.3

[ddelgrosso1]

Thank you for opening a Pull Request! Before submitting your PR, there are a few things you can do to make sure it goes smoothly:

• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Fixes #<issue_number_goes_here> 🦕

[generated-files-bot]

Warning: This pull request is touching the following templated files:

• .kokoro/continuous/node10/common.cfg - .kokoro files are templated and should be updated in synthtool
• .kokoro/continuous/node10/docs.cfg - .kokoro files are templated and should be updated in synthtool
• .kokoro/continuous/node10/test.cfg - .kokoro files are templated and should be updated in synthtool
• .kokoro/continuous/node8/common.cfg - .kokoro files are templated and should be updated in synthtool
• .kokoro/continuous/node8/test.cfg - .kokoro files are templated and should be updated in synthtool
• .github/workflows/ci.yaml - .github/workflows/ci.yaml (GitHub Actions) should be updated in synthtool

[sofisl]

Just want to confirm, did you add a legacy tag here as well?

[ddelgrosso1]

@sofisl yes I created a legacy-10 tag.

[sofisl]

Cool! Also, I think we can bump to mocha 10 in this PR. Thank you!

[ddelgrosso1]

Mocha 10 drops support for Node 12. I think we are stuck with 9.x. mochajs/mocha#4845