Issue #3211810 by alexpott, xjm, Spokje, Amber Himes Matz, Kristen Pol, lauriii: [security] Update Nightwatch and locked dev dependencies to address security issues

Issue #3211805 by xjm, Kristen Pol, longwave: Update composer/composer dev dependency in metapackages to 2.0.13

Issue #3199209 by xjm, andypost: Update Drupal 9 branches to the latest patch releases of Symfony components

SA-CORE-2021-002 by Jasu_M, effulgentsia, alexpott, mlhess, Wim Leers, Heine, pwolanin, xjm, samuel.mortenson, nwellnhof, larowlan, phenaproxima, mcrdruid

Revert "Issue #3174349 by quietone, itaran, dww, Kristen Pol: file_url_transform_relative() cannot handle URLs where the port is different from the site's request port"

This reverts commit 9a4f58da.

Issue #3174349 by quietone, itaran, dww, Kristen Pol: file_url_transform_relative() cannot handle URLs where the port is different from the site's request port

(cherry picked from commit b43c49e6)

SA-CORE-2021-001 by larowlan, stephenacrossri, siliconmeadow, mcdruid, xjm, vijaycs85, mlhess, greggles

Issue #3138795 by quietone, sja112, jungle, longwave: d6_term_node_revision references non-existent migration

(cherry picked from commit 6e1d970a)

Issue #3126746 by danflanagan8, Deepak Goyal, Neslee Canil Pinto, geek-merlin, tim.plunkett: LayoutBuilderHtmlEntityFormController breaks decoration

(cherry picked from commit 6ffbfe25)

Issue #3136406 by Spokje, codersukanta, IJsbrandy, atul4drupal, MahtabAlam, BalajiDS: Argument 1 passed to Drupal\Core\Form\SubformState::createForSubform() must be of the type array, null given

(cherry picked from commit acb4b855)

SA-CORE-2020-012 by ufku, mrf, fgm, samuel.mortenson, dww, Heine, mlhess, David_Rothstein, pwolanin, xjm, fgm, stefan.r, dsnopek, rickmanelius, David Strauss, tedbow, alexpott, dww, larowlan, kim.pepper, Wim Leers, quicksketch, mcdruid, Fabianx, effulgentsia, drumm, pandaski, Mixologic

(cherry picked from commit 1111de84)

Issue #268909 by maartenvg, raman.b, paulocs, lyricnz, Abhijith S, webchick, Freso, chx, pameeela: "0" can't be used a path alias, but no error is shown

(cherry picked from commit 29689c24)

Issue #2851504 by alexpott, vomiand, Vj, BalajiDS, cilefen, tamasd: "Illegal choice 0 in Book element" when switching the book outline field from anything to "- None - "

(cherry picked from commit 4397d8d5)

Issue #3179875 by greg.1.anderson, longwave, catch, Mixologic: Path repositories need to be listed first for Composer 2

Issue #3181173 by longwave, pefferen, JD_1, larowlan: Drupal 8.9.7 breaks Book Settings Form Validation

(cherry picked from commit 23116573)

Issue #3156651 by alexpott, dww, pfrenssen, Kristen Pol, xjm, andypost, Gábor Hojtsy, bradjones1: Prevent Drupal 8.9 and 9.0 from being installed on PHP 8

Issue #3014969 by TR, longwave, Abhijith S, joachim, shimpy: Unescaped "@" in ContextProviderInterface doc comment

(cherry picked from commit 2b76f575)
(cherry picked from commit dd91bf1d)