👻 Support seed build args. (konveyor#503)

Better support for test run analysis with seed PRs using 
`--build-arg SEED_PROJECT <url>`
`--build-arg SEED_BRANCH <branch> `

Example:
```
$ docker build . -t quay.io/jortel/tackle2-hub:latest \
  --build-arg 'SEED_PROJECT=jortel/tackle2-seed' \
  --build-arg 'SEED_BRANCH=add-targets' \
  && docker push quay.io/jortel/tackle2-hub:latest
```

Signed-off-by: Jeff Ortel <[email protected]>

Dockerfile

@@ -2,7 +2,9 @@ FROM registry.access.redhat.com/ubi9/go-toolset:latest as builder
 ENV GOPATH=$APP_ROOT
 COPY --chown=1001:0 . .
 RUN make docker
-RUN git clone https://github.com/konveyor/tackle2-seed
+ARG SEED_PROJECT=konveyor/tackle2-seed
+ARG SEED_BRANCH=main
+RUN git clone --branch ${SEED_BRANCH} https://github.com/${SEED_PROJECT}
 
 FROM quay.io/konveyor/static-report as report