Support installing multiple Typst versions in a single workflow step

[yusancky]

The executable-name option was requested in #49 and added in v4.3.0. Users now have a clear need to install multiple Typst versions in the same workflow for compatibility testing or side-by-side usage.

Consider extending the action to accept a list of { typst-version: executable-name } entries to allow install multiple Typst versions in a single workflow uses: step.

[YDX-2147483647]

If this feature parallelizes network acesss, it might also reduce CI time from ~10 sec to ~2 sec.

Background

The typst document requires artifacts compiled from other programs. Therefore, it's easier to install multiple typst compilers in the same job rather than using jobs.*.strategy.matrix.
https://github.com/typst-community/wasm-minimal-protocol/blob/21af62e1dcc167daabdd3c79913dc7a16d7c7963/.github/workflows/ci.yml#L60-L93