Prepare Bootstrap v6.0.0-alpha.1 release (#42997)

* chore(release): prepare Bootstrap 6 alpha

Update release guidance and version tooling for the first Bootstrap 6
alpha from main. Remove stale v6-dev workflow references, pin the
prerelease in agent skills, and make future version updates reliable.

* chore(dist): rebuild for v6.0.0-alpha.1

* docs: use the local logo in the README

Load the tracked Bootstrap logo instead of the deployed documentation
asset, and remove the obsolete fixed height.

* fix(docs): keep the README logo path spellcheckable

Use the literal version placeholder in the local logo path so cspell does
not parse the percent-encoded bracket as an unknown word.

Release v5.3.8 (#41669)

* Bump version

* Run dist

* Unrelated new docs error

Release v5.3.7 (#41509)

Release v5.3.6 (#41406)

* Update to v5.3.6

* Rebuild

* Rebuild

Bump to v5.3.5 (#41348)

* Bump to v5.3.5

* Undo comment version change

* undo comment

* release again

Release v5.3.4 (#40656)

* Bump version to v5.3.4

* Dist

* Dist

* dist again

* re-run npm release

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Co-authored-by: Mark Otto <markdotto@gmail.com>

Release v5.3.3 (#39524)

* Release v5.3.3

* Dist

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Co-authored-by: XhmikosR <xhmikosr@gmail.com>

Release v5.3.2 (#39173)

* Bump version to 5.3.2

* Dist

Release v5.3.1 (#38956)

* Bump version to 5.3.1

* Dist

Release v5.3.0 (#38657)

* Bump version to 5.3.0

* Dist