gclient sync frequent ratelimits, unable to clone repo

Hey all,

as of recently it's getting harder and harder for me to clone the whole flutter source tree because of ratelimits:
```
Klone nach 'flutter-3.41.2-mirrored' …
remote: Enumerating objects: 16575, done.
remote: Counting objects: 100% (16575/16575), done.
remote: Compressing objects: 100% (13489/13489), done.
remote: Total 16575 (delta 3630), reused 7660 (delta 2247), pack-reused 0 (from 0)
Empfange Objekte: 100% (16575/16575), 32.93 MiB | 2.90 MiB/s, fertig.
Löse Unterschiede auf: 100% (3630/3630), fertig.
Hinweis: Wechsle zu '90673a4eef275d1a6692c26ac80d6d746d41a73a'.

Sie befinden sich im Zustand eines 'losgelösten HEAD'. Sie können sich
umschauen, experimentelle Änderungen vornehmen und diese committen, und
Sie können alle möglichen Commits, die Sie in diesem Zustand machen,
ohne Auswirkungen auf irgendeinen Branch verwerfen, indem Sie zu einem
anderen Branch wechseln.

Wenn Sie einen neuen Branch erstellen möchten, um Ihre erstellten Commits
zu behalten, können Sie das (jetzt oder später) durch Nutzung von
'switch' mit der Option -c tun. Beispiel:

git switch -c

Oder um diese Operation rückgängig zu machen:
git switch -

Sie können diesen Hinweis ausschalten, indem Sie die Konfigurationsvariable
'advice.detachedHead' auf 'false' setzen.

62>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "7d77fb7fd66d8a5640618ad32c71fdeb7d3e02df" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib failed; will retry after a short nap...
65>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "564023aa53767b5f60b3a556f0a025b7b7e8241e" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/third_party/abseil-cpp failed; will retry after a short nap...
62>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "7d77fb7fd66d8a5640618ad32c71fdeb7d3e02df" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib failed; will retry after a short nap...
65>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "564023aa53767b5f60b3a556f0a025b7b7e8241e" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/third_party/abseil-cpp failed; will retry after a short nap...
72>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "19042c8921f35f7bec56b9e5c96c5f5691588ca8" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/vulkan-deps/spirv-tools/src failed; will retry after a short nap...
73>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "a4f8ada9f4f97c45b8c89c57997be9cebaae65d2" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/vulkan-deps/vulkan-headers/src failed; will retry after a short nap...
62>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "7d77fb7fd66d8a5640618ad32c71fdeb7d3e02df" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib failed; will retry after a short nap...
65>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "564023aa53767b5f60b3a556f0a025b7b7e8241e" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/third_party/abseil-cpp failed; will retry after a short nap...
62>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "7d77fb7fd66d8a5640618ad32c71fdeb7d3e02df" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib failed; will retry after a short nap...
65>WARNING: subprocess '"git" "-c" "core.deltaBaseCacheLimit=2g" "fetch" "origin" "564023aa53767b5f60b3a556f0a025b7b7e8241e" "--no-tags" "--depth=1"' in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/third_party/abseil-cpp failed; will retry after a short nap...
Syncing projects: 74% (76/102) engine/src/flutter/third_party/swiftshader
engine/src/flutter/third_party/zlib (ERROR)
----------------------------------------
[0:00:29] Started.
[0:00:29]

________ running 'git init /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib' in '/home/hannes/devel/flutter-3.41.2-mirrored'

[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29]
[0:00:29] Initialized empty Git repository in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib/.git/
[0:00:31] fatal: unable to access 'https://chromium.googlesource.com/chromium/src/third_party/zlib.git/': The requested URL returned error: 429
[0:00:35] fatal: unable to access 'https://chromium.googlesource.com/chromium/src/third_party/zlib.git/': The requested URL returned error: 429
[0:00:39] _____ Conflicting directory found in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib. Moving to /home/hannes/devel/flutter-3.41.2-mirrored/_bad_scm/engine/src/flutter/third_party/zlibsk1wha5e.
[0:00:39]
[0:00:39]
________ running 'git init /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib' in '/home/hannes/devel/flutter-3.41.2-mirrored'

[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39]
[0:00:39] Initialized empty Git repository in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib/.git/
[0:00:41] fatal: unable to access 'https://chromium.googlesource.com/chromium/src/third_party/zlib.git/': The requested URL returned error: 429
[0:00:45] fatal: unable to access 'https://chromium.googlesource.com/chromium/src/third_party/zlib.git/': The requested URL returned error: 429
----------------------------------------
Error: Command 'git -c core.deltaBaseCacheLimit=2g fetch origin 7d77fb7fd66d8a5640618ad32c71fdeb7d3e02df --no-tags --depth=1' returned non-zero exit status 128 in /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib

Warnings:
Conflicting directory /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/flutter/third_party/zlib moved to /home/hannes/devel/flutter-3.41.2-mirrored/_bad_scm/engine/src/flutter/third_party/zlibsk1wha5e.
Conflicting directory /home/hannes/devel/flutter-3.41.2-mirrored/engine/src/third_party/abseil-cpp moved to /home/hannes/devel/flutter-3.41.2-mirrored/_bad_scm/engine/src/third_party/abseil-cpp1xc1z6kn.
```
`429` from the remote means ratelimit AFAICT.

This makes it really hard for me to build the development artifacts for flutter-pi: https://github.com/ardera/flutter-ci/actions/runs/24032886086/job/70100991441

I already tried setting .gitcookies for chromium.googlesource.com (the `generate password` link here: https://chromium.googlesource.com/?format=HTML) because I thought authenticated requests get a higher ratelimit. But it's still the same problem.

My use-case is not thaat demanding. I think I'm already running into this after 2-3 clones locally. My CI does 3 full clones, one for each OS.

What can I do to resolve this?