Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/f2b9394b9b16
Author: RickyChien <RickyChien@users.noreply.github.com>
Desc: Merge pull request #26508 from RickyChien/bug-1103819

Bug 1103819 - Enable parallel build by default r=@cctuan

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https://hg.mozilla.org/integration/gaia-central/rev/742d70227abf
Author: Ricky Chien <ricky060709@gmail.com>
Desc: Bug 1103819 - Enable parallel build by default
Bumping manifests a=b2g-bump