Revert "Update to Bazel 7"

This reverts commit 323911941086e3c9652b98a319bcbd7dd5c9210c.

Reason for revert: Breaking Build-Mac-Clang-x86_64-Debug-Fontations and Housekeeper-PerCommit-CheckGeneratedFiles

Original change's description:
> Update to Bazel 7
>
> In particular this allows us to use https://bazel.build/reference/be/c-cpp#cc_library.implementation_deps
>
> Note that to update to Bazel 8, we will need to migrate to Bazel
> modules https://bazel.build/external/overview#bzlmod
>
> We do have to disable some tests that start failing, not because
> anything changed with how the C++ code was made, but with how
> the Bazel rules make files available. We don't have the staffing
> to investigate these thoroughly at the moment, so I've disabled
> the Bazel testing of CanvasKit (we still do BazelBuild) and the
> experimental Bazel-test-on-android rules.
>
> Change-Id: I21371c8d6a7a28babe2b5242dfeb61290726998a
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/897100
> Reviewed-by: Ben Wagner <bungeman@google.com>

Change-Id: I1c0ecdc2206716453a9bb1431f091f605d383a08
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/897636
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Kaylee Lubick <kjlubick@google.com>