CAPI E2Es failing to start in some CAPI provider's release branches

CAPI E2Es failing to start in some CAPI provider's release branches.

Failing with the following error:

`go: errors parsing go.mod:94/tmp/tmp.ssf1LXKrim/go.mod:5: unknown directive: toolchain`

https://prow.ci.openshift.org/view/gs/test-platform-results/pr-logs/pull/openshift_cluster-api/199/pull-ci-openshift-cluster-api-master-e2e-aws-capi-techpreview/1765512397532958720#1:build-log.txt%3A91-95

4.15    

Always

    1.
    2.
    3.
    

  This is because the script launching the e2e is launching it from the `main` branch of the cluster-capi-operator (which has some backward incompabible go toolchain changes), rather than the correctly matching release branch.