Update Traffic Portal v2 builder and CI to NodeJS 18

[zrhoffman]

8005

• Adds a new builder for Traffic Portal v2 to the Docker Hub (created in INFRA-25760), apache/traffic_portal_v2_builder
• Updates GitHub Actions for TPv2 to use NodeJS 18

Note that this drops TPv2 support for CentOS 7.

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## Which Traffic Control components are affected by this PR?

• Build system
• Automation - GHAs

What is the best way to verify this PR?

Verify that tests pass

PR submission checklist

• [x] This PR has tests
• [ ] This PR has documentation
• [ ] This PR has a CHANGELOG.md entry
• [x] This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 74.17%. Comparing base (ef3fc6a) to head (a47d2f1). Report is 16 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #8005 +/- ## ========================================== - Coverage 74.36% 74.17% -0.20% ========================================== Files 121 121 Lines 5548 5642 +94 Branches 908 922 +14 ========================================== + Hits 4126 4185 +59 - Misses 1351 1383 +32 - Partials 71 74 +3 ``` | [Flag](https://app.codecov.io/gh/apache/trafficcontrol/pull/8005/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=apache) | Coverage Δ | | |---|---|---| | [traffic_portal_v2](https://app.codecov.io/gh/apache/trafficcontrol/pull/8005/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=apache) | `74.17% <ø> (-0.20%)` | :arrow_down: | | [unit_tests](https://app.codecov.io/gh/apache/trafficcontrol/pull/8005/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=apache) | `74.17% <ø> (-0.20%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=apache#carryforward-flags-in-the-pull-request-comment) to find out more.

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