Support bazel 7

[furtib]

Why:
We want to extend our support for newer Bazel versions

What:
Added a variable BAZEL_VERSION to the generated defs.bzl
Made the attribute _whitelist_function_transition conditional. It is only added to the attributes list if the user uses a Bazel version older than 6.

Addresses:
#108

Note:
The dictionary concatenation used may have been introduced in Bazel 6

[furtib]

We should test this somehow before merging.

We should run unittests and FOSS on Bazel 7.7.0 too.
Should I make the necessary changes for that here or in a separate PR?

[Szelethus]

We should test this somehow before merging.

We should run unittests and FOSS on Bazel 7.7.0 too. Should I make the necessary changes for that here or in a separate PR?

I think all things considered, it is appropriate to add the tests in this PR.

[furtib]

Sorry, that comment was a bit outdated.
I have already started working on a more robust GitHub action suite so that it can be easily extended to multiple Bazel versions.
see #115

[furtib]

I had to comment out configs in the per_file part of the codechecker macro; this should not be necessary after #113 is merged

[Szelethus]

Alright, I can't find a catch in here. The patch looks great!

[Szelethus]

Alright, lets do it. Since the github CI changes land here at the same time, we can't really move the test changes to a separate PR, so this is as lean as this patch can get.