Rework Update workflows and remove master docs

[iethree]

1. Removes the master branch docs, which should never be committed or published
2. .gitignores the master branch docs dir, so they cannot be committed
3. Reworks the update docs workflow
   a. There's only one workflow now, instead of 3
   b. It runs nightly on a cron with a configured LATEST_VERSION
   c. It can be run manually and takes a single major version argument, rather than two branch names.

See discussion thread: https://metaboat.slack.com/archives/C0ACAG2CXHV/p1785433663417059

Best to review the second commit which is much smaller and contains all the workflow changes 66da972

[gantoreno]

Nice! One non-blocking thing but probably worth knowing is that the clojure script still categorizes master as a publishable artifact

docs.metabase.github.io/script/update_docs_for_branchname.clj

Lines 37 to 42 in 66da972

	[category
	release-num] (u/categorize-branchname target-branch)
	command (-> (cond
	(= category :master)
	"./script/docs master --set-version master"

And it even tests for it

docs.metabase.github.io/script/_test/all.clj

Lines 10 to 27 in 66da972

	(def ^:private branches ["master"
	"release-x.49.x"
	"release-x.50.x"
	;; Current release branch:
	(str "release-x." (u/config-docs-version) ".x")
	"any-other-branch"])
	(def ^:private source-branch-name "my-new-docs-branch")
	(def ^:private expected
	(assoc {"master" {:publish-branch-docs? true
	:update-docs-command (str "./script/docs master --set-version master --source-branch " source-branch-name)}
	"release-x.49.x" {:publish-branch-docs? true
	:update-docs-command (str "./script/docs release-x.49.x --set-version v0.49 --source-branch " source-branch-name)}
	"release-x.50.x" {:publish-branch-docs? true
	:update-docs-command (str "./script/docs release-x.50.x --set-version v0.50 --source-branch " source-branch-name)}
	"any-other-branch" {:publish-branch-docs? false
	:update-docs-command "Unpublishable branchname"}}

For correctness, going forward it might be a good idea to invert that assertion

[gantoreno]

Does this need a default? Is it required?

[iethree]

i think it's helpful to demonstrate the format (99 vs v99 vs release-x.99.x)

[iethree]

clojure script still categorizes master as a publishable artifact

I want clojure outta this repo in the medium term, but I'm gonna let @bpander do that as part of rationalizing the build process. I don't want to spend too much time tightening up a script that we plan to delete

[alexyarosh]

Ryan you are my favorite person