Add build_environment directive to framework

[scaronni]

Implements #555.

Add a new global build_environment directive, that can contain a path to a file that is sourced in the DKMS shell when building modules. This allows to specify arbitrary directories and settings for custom compilers.

Test the whole thing by enabling full test on Oracle Linux.

On Oracle Linux 8 & 9, the UEK kernel variant is compiled with GCC from a software collection; so run the whole set of tests (that otherwise would be identical to the AlmaLinux ones) using the build_environment directive, the GCC software collection script and the UEK kernel.

On Oracle Linux 10, just use the UEK kernel which is compiled with the default system compiler.

[anbe42]

For more genericity, is it possible to use ${kernelver} or similar in the build_environment directive?

Is the script run in a context where it can evaluate ${kernelver}? (To be able to apply different settings for 6.7.8-amd64-foo and 6.10.23-bar?)

[scaronni]

For more genericity, is it possible to use ${kernelver} or similar in the build_environment directive?

Is the script run in a context where it can evaluate ${kernelver}? (To be able to apply different settings for 6.7.8-amd64-foo and 6.10.23-bar?)

I thought about this, I think it should work, as the variables that are exported when calling the source script are available during the execution. Will make a test and amend the man page if it works.

[scaronni]

I confirm ${kernelver} works inside the environment file being sourced. I've amended the comment in dkms_framework.conf.in and the man page.

I'll merge this once the tests are successfully executed.

[scaronni]

Doh, Github is DDOSing Canonical:

Err:171 http://security.ubuntu.com/ubuntu noble-updates/main amd64 linux-firmware amd64 20240318.git3b128b60-0ubuntu2.19
  429  Too Many Requests [IP: 185.125.190.82 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/l/linux-firmware/linux-firmware_20240318.git3b128b60-0ubuntu2.19_amd64.deb  429  Too Many Requests [IP: 185.125.190.82 80]
Fetched 318 MB in 22s (14.5 MB/s)