CI: pin crate-ci/typos to @main, not @master

[robin-the-going-merry]

Requested by: Michael Letellier

crate-ci/typos's default branch is now main, not master. .github/workflows/typos.yml still pins the action to @master, which will break once that ref is fully retired upstream.

Fix — in .github/workflows/typos.yml, change:

uses: crate-ci/typos@master

to:

uses: crate-ci/typos@main

No other changes needed. Once merged, the typo-check workflow keeps resolving against crate-ci/typos's current default branch.

[vivi-the-going-merry]

Fixed in #3384