beaker: bootstrap tests fail with Mock 4.1

[praiskup]

:: [ 16:06:39 ] :: [   PASS   ] :: Command 'copr-cli build @copr/TEST1685981192645094862-bootstrap-project https://pagure.io/copr/copr-test-sources/raw/master/f/hello-2.8-1.src.rpm --nowait' (Expected 0, got 0)
:: [ 16:06:39 ] :: [   PASS   ] :: Command 'parse_build_id' (Expected 0, got 0)
:: [ 16:11:46 ] :: [   FAIL   ] :: Command 'copr watch-build 2914435' (Expected 0, got 4)

The corresponding build log snippet

No matches found for the following disable plugin patterns: local, spacewalk, versionlock
Copr repository                                 456  B/s | 257  B     00:00    
Red Hat Enterprise Linux - BaseOS               0.0  B/s |   0  B     00:00    
Errors during downloading metadata for repository 'rhel-baseos':
  - Curl error (77): Problem with the SSL CA cert (path? access rights?) for https://cdn.redhat.com/content/dist/rhel8/8/x86_64/baseos/os/repodata/repomd.xml [error setting certificate file: /etc/rhsm/ca/redhat-uep.pem]
Error: Failed to download metadata for repo 'rhel-baseos': Cannot download repomd.xml: Curl error (77): Problem with the SSL CA cert (path? access rights?) for https://cdn.redhat.com/content/dist/rhel8/8/x86_64/baseos/os/repodata/repomd.xml [error setting certificate file: /etc/rhsm/ca/redhat-uep.pem]
WARNING: DNF command failed, retrying, attempt #2, sleeping 10s
No matches found for the following disable plugin patterns: local, spacewalk, versionlock

[praiskup]

This is related to: rpm-software-management/mock#1088

IOW we do --use-bootstra-image fedora:38 for the epel-8 chroot, which forces Mock to install EL8 packages into the Fedora 38 bootstrap chroot (which itself is a convoluted and rather weird use-case).

[praiskup]

Done.