telepathy-glib: boneyard

The Telepathy formulae are being shipped off to the boneyard.

1) The number of downloads per formula in terms of Bottles is less than 30 in
the space of 3 months.

2) Two of them were moved onto development releases in November and nobody noticed.

3) telepathy-gabble's executable has been broken since submission and nobody noticed.

4) Making telepathy-gabble's executable function requires significant changes to
d-bus, including enforcing a mandatory X11 dependency on telepathy-gabble users.

5) It's not particularly simple to write tests for the formulae which means they're
more likely to break without CI noticing.

Closes Homebrew/homebrew#49052.