Enable Retrying Failed Tests in mr:e2e Jobs

Problem

The mr:e2e jobs in CustomersDot MRs do not currently have a way to automatically retry failed tests. Other E2E jobs run a retry on test failures to help rule out flakiness due to non-functional causes (temporary infrastructure issues, Zuora performance issues, etc.)

Proposal

See if the available retry_failed_rspec_examples script (which is also available in the .with-rspec job) can be used for mr:e2e jobs to allow retrying failed tests.