Issue #3439892 by SolimanHarkas, pradhumanjain2311, vensires: Fix Language tests that rely on UID1's super user behavior

This reverts commit 5a9ce8cf.

Issue #540008 by kristiaanvandeneynde, Spokje, daffie, clayfreeman, alexpott, eelkeblok, michaelfavia, ianthomas_uk, zaporylie, johnwebdev, abhisekmazumdar, anmolgoyal74, greggles, quietone, shaal, catch, rivimey, AaronMcHale, Berdir, ndf, xjm, finne, Wim Leers, esolitos, heddn, webchick, Bojhan, andypost, efpapado, benjifisher, lauriii, Gábor Hojtsy, moshe weitzman, harings_rob: Add a container parameter that can remove the special behavior of UID#1

Issue #2575105 by Berdir, catch, longwave, quietone, kristiaanvandeneynde, andypost, alexpott, mathilde_dumond, pradhumanjain2311, amateescu, Wim Leers, xjm: Use cache collector for state

Issue #3433088 by mondrake, Spokje: Method getMockForAbstractClass() of class PHPUnit\Framework\TestCase is deprecated in PHPUnit 10 - Step 1 interfaces

Issue #3433052 by mondrake: Fix remaining return*() methods of class PHPUnit\Framework\TestCase deprecated in PHPUnit 10

Issue #3421017 by mohit_aghera, smustgrave: Convert LanguageNegotiation plugin discovery to attributes

Issue #2613222 by webflo, alexpott, ameymudras, pooja saraah, _utsavsharma, penyaskito, Janvi Dasani: Language module shouldn't alter config in sync mode

Issue #3353210 by mondrake, PrabuEla, Spokje: [PHPUnit 10] @dataProvider methods must be declared static and public

Issue #3382581 by phenaproxima, borisson_, larowlan, Wim Leers, quietone: Add new `EntityBundleExists` constraint

Issue #3385550 by lauriii, Gauravvvv, sboden, Shabbir, longwave: Language negotiation breaks updating Drupal 9 to 10

Issue #3384936 by marvil07, vbouchet, smustgrave, xjm, joachim: Use the API to set up languages in tests that are not specifically testing the language form

Issue #3404273 by mstrelan, smustgrave: Fix strict type errors: Convert FormattableMarkup to strings (simple replacement) in core Functional tests

Issue #2484991 by znerol, voleger, andypost, dww, anmolgoyal74, markdorison, ankithashetty, larowlan, daffie, alexpott: Add the session to the request in KernelTestBase, BrowserTestBase, and drush

Revert "Issue #2484991 by znerol, voleger, andypost, dww, anmolgoyal74, markdorison, ankithashetty, daffie, alexpott, larowlan: Add the session to the request in KernelTestBase, BrowserTestBase, and drush"

This reverts commit 48a7cf12.

Issue #2484991 by znerol, voleger, andypost, dww, anmolgoyal74, markdorison, ankithashetty, daffie, alexpott, larowlan: Add the session to the request in KernelTestBase, BrowserTestBase, and drush

Issue #3405800 by alexpott, phenaproxima, Wim Leers, bircher, larowlan: Config collections do not trigger configuration events consistently

Issue #3351458 by dburiak, Mingsong, Mahima_Mathur23, sthomen, smustgrave, catch, alexpott: [regression] Language switcher block returns links to node on the frontpage

Issue #3389282 by quietone, smustgrave, alexpott: Fix spelling for words that are only misspelled  in comments

Issue #3386458 by catch, quietone, alexpott, larowlan: Add GenericModuleTestBase and use it to test general module things

Issue #3388365 by catch, larowlan, bbrala, smustgrave: Distribute @group #slow tests between test runners and mark more tests

Issue #2914251 by quietone, maxocub, masipila, larowlan: Move forum related logic from taxonomy migrations to new forum migrations

Issue #296693 by tedbow, omkar.podey, sun, ilya.no, JeroenT, tim.plunkett, catch, hooroomoo, ridhimaabrol24, boombatower, paulocs, Damien Tournoud, Xano, pwolanin, chx, webchick, stella, quietone, Bojhan, smustgrave, lauriii, benjifisher, gabesullice: Restrict access to empty top level administration pages

Issue #3341682 by Wim Leers, phenaproxima, borisson_, catch, alexpott: New config schema data type: required_label

Issue #3375959 by znerol, catch, bradjones1: Add a way to delay executions in test runner until terminate event completed in the child site

Issue #3376281 by Indrapatil, nlisgo, longwave, smustgrave: Random machine names no longer need to be wrapped in strtolower()

Issue #3377030 by Wim Leers, borisson_, smustgrave: Add validation constraint to `type: label`: disallow multiple lines

Issue #3219513 by quietone, smustgrave, Vidushi Mehta, sourabhjain, rpayanm, longwave, xjm, dww, catch: Fix spelling for words used once, beginning with 'n' -> 'p', inclusive