There's a merged pull request on the void-packages repository

glib,glibmm2.68: update to 2.78.0.
https://github.com/void-linux/void-packages/pull/46097

Description:
- libsigc++3: update to 3.4.0.
- glib: update to 2.78.0.
- glibmm2.68: update to 2.78.0.

#### Testing the changes
- I tested the changes in this PR: **briefly**


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