bundler: temporarily remove `leafRSA3072` testcases.
bundler: temporarily remove `leafRSA3072` testcases.

The `leafRSA3072` test file, (`bundler/testdata/cfssl-leaf-rsa3072.pem`)
expired and breaks tests. A proper fix would be to regenerate this test
file but in the meantime removing the testcases fixes CI.

cloudflare/cfssl,cloudflare/cfssl,cloudflare/cfssl,cloudflare/cfssl