Fuchsia CI is failing

[RalfJung]

Between #138661 and #138653, Fuchsia CI jobs failed 4 times in a row. The errors are not always the same though:

stderr:
Cloning into '/checkout/obj/fuchsia/third_party/fuchsia-infra-bazel-rules/src'...
error: RPC failed; HTTP 429 curl 22 The requested URL returned error: 429
fatal: expected flush after ref listing

 [17:53:33.997] WARN: Projects with local changes and/or not on JIRI_HEAD:
third_party/pylibs/tomlkit (third_party/pylibs/tomlkit/src): (Has changes)
third_party/go (third_party/go): (Has changes)
third_party/pylibs/typing_extensions (third_party/pylibs/typing_extensions/src): (Has changes)
third_party/pylibs/dill (third_party/pylibs/dill/src): (Has changes)
third_party/android/platform/system/bt (third_party/android/platform/system/bt): (Has changes)
third_party/pylibs/platformdirs (third_party/pylibs/platformdirs/src): (Has changes)
third_party/pylibs/isort (third_party/pylibs/isort/src): (Has changes)

 [13:24:20.325] WARN: Projects with local changes and/or not on JIRI_HEAD:
third_party/jinja2 (third_party/jinja2/jinja2): (Has changes)
third_party/pypng (third_party/pypng/src): (Has changes)
third_party/android.googlesource.com/platform/bionic (third_party/android/platform/bionic): (Has changes)
third_party/perfetto (third_party/perfetto): (Has changes)
third_party/android/platform/system/tools/aidl (third_party/android/platform/system/tools/aidl): (Has changes)
third_party/android.googlesource.com/platform/packages/modules/Bluetooth (third_party/android/platform/packages/modules/Bluetooth/src): (Has changes)

[16:41:21.062] WARN: Projects with local changes and/or not on JIRI_HEAD:
third_party/pyyaml (third_party/pyyaml/src): (Has changes)
third_party/android/device/generic/goldfish-opengl (third_party/android/device/generic/goldfish-opengl): (Has changes)
third_party/shac-project/generic-checks (third_party/shac-project/generic-checks/src): (Has changes)
third_party/pylibs/autoflake (third_party/pylibs/autoflake/src): (Has changes)
third_party/android/platform/system/tools/aidl (third_party/android/platform/system/tools/aidl): (Has changes)
third_party/fuchsia-infra-bazel-rules (third_party/fuchsia-infra-bazel-rules/src): (Has changes)

[RalfJung]

#138690 disables the job so that we can continue landing things in the repo while the Fuchsia issue is being debugged.

@Nashenas88 wrote

If this issue is sporadic, I'd recommend retrying until we can find a solution.

I think 4 times in a row is too much to be considered "sporadic".