MBErr: Builder group name "chromium.fuzz" not found in "/opt/chromium/src/tools/mb/mb_config.pyl"

HI all,
I'm following [this](https://chromium.googlesource.com/chromium/src/+/main/testing/libfuzzer/getting_started_with_libfuzzer.md) tutorial and I have noticed that `chrome.fuzz` isn't usable anymore.

Which `group name` should we use now? At least, which options were set by it?

I would also like to understand how to build and run the fuzzer. I have with

```
# Build the fuzz target.
autoninja -C chrome/browser/ash:create_fnmatch_query_fuzzer
# Run the fuzz target.
./out/libfuzzer/create_fnmatch_query_fuzzer
```

But with no luck.

```
➜ src git:(ccbeb246d2) autoninja -C chrome/browser/ash:create_fnmatch_query_fuzzer
ninja: Entering directory `chrome/browser/ash:create_fnmatch_query_fuzzer'
ninja: fatal: chdir to 'chrome/browser/ash:create_fnmatch_query_fuzzer' - No such file or directory
➜ src git:(ccbeb246d2)
```

Thanks