igraph: update to 0.10.12

[szhorvat]

Description

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS 14.4.1 23E224 arm64
Xcode 15.3 15E204a

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:
@nerdling for port igraph.

[szhorvat]

Added the py-igraph update to the same PR because testing py-igraph and its dependency igraph goes hand-in-hand, and I need the py-igraph update to happen after igraph. I am a maintainer of both ports. Hoping for a timely merge.