[Libtasn1] disable documentation

[xandox]

Documentation generates by gtk tool which not must exists. For PR #15605

• Which triplets are supported/not supported? Have you updated the CI baseline?

  same, No

• Does your PR follow the maintainer guide?

  yes

• If you have added/updated a port: Have you run ./vcpkg x-add-version --all and committed the result?

  Yes

[dg0yt]

This PR changes options to configure which default to being off anyway AFAIK. We have seen this package fail at least on osx already before configure due to failed attempts to run gtkdocize during autoreconf (#17098). If this PR runs into this problem, too:

I tried to get this solved for CI via provisioning (#17227), and I made other proposals to solve this also for vcpkg users. The last attempt, #17406, doesn't seem to work as well as I thought for other packages, but that approach might perhaps be turned around in the libtasn1's portfile by adding

set(ENV{GTKDOCIZE} true)

before calling vcpkg_configure_make. (I cannot test this at the moment.)

[xandox]

gt-html is on by default according to configure --help

[dg0yt]

There are many changes to formatting. Some are improvements but aren't IMO.

[PhoebeHui]

@xandox, thanks for the PR!

[xandox]

Formatting is fixed. Sorry for that, did not notice my autoformat job.

[PhoebeHui]

No problem, thanks for your contribution!

[PhoebeHui]

The CI failed due to #17057.

[ras0219-msft]

This LGTM, thanks for the improvement!