change shell to bash to allow bash specific features

[pranithk]

fixes: 3598
Change-Id: Ic5fd8ab840d179dbf163ffa97341c94f2bddf6eb

[pranithk]

/run regression

[mscherer]

I disabled the gating, as the situation right now is a bit unstable. I would suggest move at least smoke test to github actions.

[mscherer]

/run regression

[pranithk]

@mscherer Builds are failing with:

05:46:41 ERROR: Command failed: 
05:46:41  # /usr/bin/dnf --installroot /var/lib/mock/fedora-35-i686-bootstrap/root/ --releasever 35 --setopt=deltarpm=False --allowerasing --disableplugin=local --disableplugin=spacewalk --disableplugin=versionlock install dnf dnf-plugins-core --setopt=tsflags=nocontexts
05:46:41 No matches found for the following disable plugin patterns: local, spacewalk, versionlock
05:46:41 local                                           1.1 kB/s | 196  B     00:00    
05:46:41 Errors during downloading metadata for repository 'local':
05:46:41   - Status code: 404 for https://kojipkgs.fedoraproject.org/repos/f35-build/latest/i386/repodata/repomd.xml (IP: 38.145.60.20)
05:46:41 Error: Failed to download metadata for repo 'local': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried

Alternatively we can disable 32 bit builds too for now. We anyway don't support it.

[mscherer]

So right now, the CI need to be cleaned up (eg, remove the old tests, eg, clean harder), but what block is getting a review it seems. The CI is no longer blocking