Before this commit, the fuzzer dependend on clusterfuzz, which uses
protobuf 3.20. Since fuzzer-bot depended on common subpackage as well
and also common (and the other packages) require protobuf, we had to use
protobuf 3.20 everywhere. This old dependency however means that a lot
of packages can't be used in their "newer" versions, because they depend
on newer protobuf versions.
This commit splits the fuzzer into a separate fuzzer-runner that is
executed in a separate process inside a separate venv. fuzzer-runner
executes the clusterfuzz-heavy operations (e.g. fuzzing) and isolates the
clusterfuzz dependency, so that the rest of the system can use newer
protobuf version.
* split `fuzzer-bot` in `fuzzer-runner` and `fuzzer-bot`
* have a "full" optional dependency group in `common`, including `openlit`
and `protobuf`, so that `fuzzer-runner` can use the lite version of `common`
without bringing those heavy deps
* move `FuzzConfiguration`/`BuildConfiguration` in a separate common file
that doesn't require to load all protobuf files. Again, in this way
other components can just depend on the `common` "lite" version and not
require protobuf stuff
* add `fuzzer-runner` as a separate venv inside the `fuzzer-bot` container
* add `RunnerProxy` class in fuzzer package to provide an interface to
interact with the fuzzer-runner binary.
Henrik Brodin