With the --web adapter it happens that we get 404 because it might be just too fast for some hosters to create the file and access it through the web near-instantaneously.
I guess this is related to their storage and file system caches, maybe also PHP stat cache?

Current workaround: It will usually succeed after some tries...

./cachetool stat:clear --web=SymfonyHttpClient --web-url=https://.../ --web-path=./public/ --web-host

It is currently holding us a bit back on systems where we can't use --fcgi.

Splitting this off from #199 which is about retrying the whole procedure which can probably mostly be avoided in this case.