Add GitHub product API settings

[tungyhardDevOps]

Description

Closes #8819.

This PR allows API clients to associate a GitHub project and an existing GitHub configuration while creating a product through POST /api/v2/products/.

The product serializer now accepts the optional, write-only github_project and github_configuration fields:

github_project = serializers.CharField(allow_blank=True, max_length=200, required=False, write_only=True)
github_configuration = serializers.PrimaryKeyRelatedField(
    allow_null=True,
    queryset=GITHUB_Conf.objects.all(),
    required=False,
    write_only=True,
)

After the product is created, the serializer creates the existing GITHUB_PKey relation when either GitHub field was supplied:

def create(self, validated_data):
    github_project = validated_data.pop("github_project", "")
    github_configuration = validated_data.pop("github_configuration", None)
    product = super().create(validated_data)
    if github_project or github_configuration:
        GITHUB_PKey.objects.create(
            product=product,
            git_project=github_project,
            git_conf=github_configuration,
        )
    return product

Test results

Added unittests/test_product_github_api.py covering:

• Creating a product with a GitHub project and configuration.
• Creating a product without GitHub settings.
• Rejecting an unknown GitHub configuration without creating the product.

The focused Django tests passed:

Ran 3 tests in 8.803s

OK

Ruff 0.15.21 passed for both changed files. EXE002 was excluded locally because Docker Desktop marks Windows bind-mounted files as executable; Git records both files with normal 100644 modes.

All checks passed!

Documentation

Please update any documentation when needed in the documentation folder)

Checklist

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• Features/Changes should be submitted against the dev.
• Bugfixes should be submitted against the bugfix branch.
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• Your code is python 3.13 compliant.
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• Add applicable tests to the unit tests.
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[tungyhardDevOps]

hello @Maffooch @blakeaowens could you please give this a review? thank you