snapcast: fix compilation with boost 1.88.0

snapcast: fix compilation with boost 1.88.0

Boost upgrade hit Snapcast hard again: the process needs to be updated!

This patch is a patchset from badaix/snapcast@develop.
It is based on the following upstream commits:
badaix/snapcast@901b79a213b1 ("Build failure with boost 1.88.0 #1367")
badaix/snapcast@ffb086b4b331 ("Define BOOST_PROCESS_VERSION=1 globally")
badaix/snapcast@c37a76a4aba9 ("Add missing includes")
badaix/snapcast@571f6a8f6953 ("Include process v1 headers for Boost version >= v1.88.0")

Refs: 3585ddfc446c ("boost: Updates package to version 1.88.0")

Signed-off-by: Szabolcs Hubai <[email protected]>