libsvm: update to 3.35 and add py312-libsvm subport

[nilason]

Description

Update libsvm to version 3.35.

As this rev-bumps orfeotoolbox, I took the opportunity to include a fix for livecheck regex (which used to include rc versions as well).

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 14.6.1 23G93 arm64
Xcode 15.4 15F31d

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint --nitpick?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@ryandesign for port php-svm.
@stromnov for port py-pymvpa.

[nilason]

The CI runners bailed out after revbumping all dependants, so I resorted to "skip ci" for php-svm and py-pymvpa.