Deps: Stop ignoring the agp update

The AGP update no longer needs to be synced with other in-house
library and client projects (except for GBKit). As such, there is no
need for Dependabot to ignore them anymore.

This limitation got lifted due to the fact that:
- 'FluxC' got vendored into this project, and thus the need to sync the
AGP version with WCAndroid is no longer relevant (paaHJt-7hU-p2).
- It has been decided that any project that requires compatibility with
composite build on a library level, they will have to make the change
themselves, when and if needed (paaHJt-6Qv-p2).

------------------------------------------------------------------------

About the 'GBKit' exception, following the below PR's approach, a
product engineer should be able to replicate a future AGP update without
too much trouble:

PS: [Build] Update Gradle to 8.12.1 and AGP to 8.8.1 #21680
- #21680

Thus, it is better to unblock such automated AGP updates, based on
Dependabot, instead of leaving them become stale for too long.

Author: ParaskP7

.github/dependabot.yml

@@ -18,11 +18,6 @@ updates:
         exclude-patterns:
           - "org.jetbrains.kotlinx*"
     ignore:
-      # The Android Gradle Plugin is a dependency that needs to be in sync with other
-      # in-house libraries due to compatibility with composite build.
-      - dependency-name: "com.android.tools.build:gradle"
-      - dependency-name: "com.android.application"
-      - dependency-name: "com.android.library"
       # Bumping 2.13.3 to the newest version requires lots of changes, including changes to
       # Gutenberg. As such, and as agreed, any update is paused. For more details, see
       # https://github.com/wordpress-mobile/WordPress-Android/pull/17936#issuecomment-1553227875