Use regular UBI as base for dev images

[Molter73]

Description

Non-minimal UBI images come with gdbserver pre-installed, so replacing it in the current dockerfile via sed seems like the best way to keep it up to date without having to resort to any weird workarounds.

The PR also does some cleanup, moving certain make clean commands and .gitignore lines to be closer to the place they are actually used.

Checklist

• Investigated and inspected CI test results

Testing Performed

• Build the dev image and make sure it can be debugged from a k8s deployment.

[github-actions]

Kernel	Method	Without Collector Time (secs)	With Collector Time (secs)	Baseline median (secs)	Collector median (secs)	PValue
rhel.rhel-7	ebpf	247.682	581.528	181.96	356.72	🟢
rhel.rhel-7	module	246.374	445.077	185.93	285.44	🟢
rhel.rhel-8	ebpf	240.935	249.307	204.92	213.7	🟢
rhel.rhel-8	module	225.222	405.671	187.91	285.98	🟢
ubuntu-os.ubuntu-1804-lts	ebpf	248.999	232.035	206.11	213.49	🟢
ubuntu-os.ubuntu-1804-lts	module	265.68	451.922	199.27	291.54	🟢
ubuntu-os.ubuntu-2004-lts	ebpf	249.811	245.777	236.1	234.97	🟢
ubuntu-os.ubuntu-2004-lts	module	268.204	445.332	232.85	321.36	🟢
ubuntu-os.ubuntu-2204-lts	ebpf	242.258	243.055	222.56	229.05	🟢
ubuntu-os.ubuntu-2204-lts	module	253.924	419.933	213.37	287.88	🟢