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

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https://hg.mozilla.org/integration/gaia-central/rev/881e289aff99
Author: RickyChien <RickyChien@users.noreply.github.com>
Desc: Merge pull request #25286 from RickyChien/bug-1081065

Bug 1081065 - Fix broken test coverage r=@julienw

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https://hg.mozilla.org/integration/gaia-central/rev/999b72242ab7
Author: Ricky Chien <ricky060709@gmail.com>
Desc: Bug 1081065 - Fix broken test coverage
Bumping manifests a=b2g-bump