Automatic merge from submit-queue
Timeout and Max-in-flight don't report non-resource URLs correctly.
Unify error reporting for 429 and 504 to be correct for timeout and max in flight and eviction. Add better messages to eviction (removing a todo). Return the correct body content for timeouts (reason and code should be correct).
This potentially increases cardinality of 429, but because non-api urls may be under the max-inflight budget we need to report them somewhere (if something breaks and starts fetching API versions endlessly).
```release-note
The 504 timeout error was returning a JSON error body that indicated it was a 500. The body contents now correctly report a 500 error.
```
If there are 2 or more PR(s) in the queue, they will end up with
conflicts (and rechecks). So let us remove the timestamp entirely
when we generate the files.
Fixes#46814
Automatic merge from submit-queue
Fix api description
**What this PR does / why we need it**:
prefered -> preferred
the the -> the
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
