Enhancement/8196 remove duplicate tag snippet functionality

[jimmymadon]

Summary

Addresses issue:

• Remove functionality preventing GA4 from outputting tags when GTM takes over  #8196

Relevant technical choices

In addition to the IB, I have also removed the legacy selectors for the GTM / UA integration which were needed by the duplicate tag snippet code that was removed. This was originally a part of the ACs of #7992 but it was decided to incorporate this removal into this issue and #7990.

PR Author Checklist

• My code is tested and passes existing unit tests.
• My code has an appropriate set of unit tests which all pass.
• My code is backward-compatible with WordPress 5.2 and PHP 5.6.
• My code follows the WordPress coding standards.
• My code has proper inline documentation.
• I have added a QA Brief on the issue linked above.
• I have signed the Contributor License Agreement (see https://cla.developers.google.com/).

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Code Reviewer Checklist

• Run the code.
• Ensure the acceptance criteria are satisfied.
• Reassess the implementation with the IB.
• Ensure no unrelated changes are included.
• Ensure CI checks pass.
• Check Storybook where applicable.
• Ensure there is a QA Brief.

Merge Reviewer Checklist

• Ensure the PR has the correct target branch.
• Double-check that the PR is okay to be merged.
• Ensure the corresponding issue has a ZenHub release assigned.
• Add a changelog message to the issue.

[github-actions]

Build files for 837506c have been deleted.

[github-actions]

Size Change: -2.62 kB (0%)

Total Size: 1.49 MB

Filename	Size	Change
./dist/assets/js/googlesitekit-activation-********************.js	23.7 kB	+7 B (0%)
./dist/assets/js/googlesitekit-ad-blocking-recovery-********************.js	52.9 kB	+1 B (0%)
./dist/assets/js/googlesitekit-adminbar-********************.js	34.4 kB	+20 B (0%)
./dist/assets/js/googlesitekit-api-********************.js	10.1 kB	-5 B (0%)
./dist/assets/js/googlesitekit-components-gm2-********************.js	5.76 kB	-5 B (0%)
./dist/assets/js/googlesitekit-components-gm3-********************.js	10 kB	-1 B (0%)
./dist/assets/js/googlesitekit-datastore-forms-********************.js	9.11 kB	-2 B (0%)
./dist/assets/js/googlesitekit-datastore-site-********************.js	18.4 kB	-8 B (0%)
./dist/assets/js/googlesitekit-datastore-ui-********************.js	9.24 kB	-1 B (0%)
./dist/assets/js/googlesitekit-datastore-user-********************.js	24.2 kB	+2 B (0%)
./dist/assets/js/googlesitekit-entity-dashboard-********************.js	89.5 kB	-1 B (0%)
./dist/assets/js/googlesitekit-main-dashboard-********************.js	109 kB	+12 B (0%)
./dist/assets/js/googlesitekit-modules-********************.js	22 kB	-17 B (0%)
./dist/assets/js/googlesitekit-modules-adsense-********************.js	111 kB	-24 B (0%)
./dist/assets/js/googlesitekit-modules-analytics-4-********************.js	91.8 kB	-49 B (0%)
./dist/assets/js/googlesitekit-modules-analytics-********************.js	89.5 kB	-352 B (0%)
./dist/assets/js/googlesitekit-modules-pagespeed-insights-********************.js	22.5 kB	+4 B (0%)
./dist/assets/js/googlesitekit-modules-search-console-********************.js	58.9 kB	+26 B (0%)
./dist/assets/js/googlesitekit-modules-tagmanager-********************.js	30 kB	-2.19 kB (-7%)	✅
./dist/assets/js/googlesitekit-settings-********************.js	50.8 kB	-16 B (0%)
./dist/assets/js/googlesitekit-splash-********************.js	67.3 kB	+1 B (0%)
./dist/assets/js/googlesitekit-user-input-********************.js	42.3 kB	-4 B (0%)
./dist/assets/js/googlesitekit-vendor-********************.js	316 kB	-1 B (0%)
./dist/assets/js/googlesitekit-widgets-********************.js	33.5 kB	+18 B (0%)
./dist/assets/js/googlesitekit-wp-dashboard-********************.js	61.8 kB	-24 B (0%)
./dist/assets/js/runtime-********************.js	1.3 kB	-6 B (0%)

ℹ️ View Unchanged

Filename	Size
./dist/assets/css/googlesitekit-admin-css-********************.min.css	50.8 kB
./dist/assets/css/googlesitekit-adminbar-css-********************.min.css	11.1 kB
./dist/assets/css/googlesitekit-wp-dashboard-css-********************.min.css	7.38 kB
./dist/assets/js/29-********************.js	2.8 kB
./dist/assets/js/30-********************.js	2.28 kB
./dist/assets/js/31-********************.js	3.72 kB
./dist/assets/js/32-********************.js	929 B
./dist/assets/js/33-********************.js	888 B
./dist/assets/js/34-********************.js	3.12 kB
./dist/assets/js/analytics-advanced-tracking-********************.js	778 B
./dist/assets/js/googlesitekit-data-********************.js	2.18 kB
./dist/assets/js/googlesitekit-datastore-location-********************.js	2.09 kB
./dist/assets/js/googlesitekit-i18n-********************.js	3.92 kB
./dist/assets/js/googlesitekit-polyfills-********************.js	379 B

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[tofumatt]

Looks good to me! 👍🏻