Omit run URL when GITHUB_REPOSITORY or GITHUB_RUN_ID is absent - #132

github_actions() builds the URL with a template literal over two environment
variables that may be undefined. Interpolating undefined yields the literal
string 'undefined', so the result is:

    https://github.com/undefined/actions/runs/undefined

That is a real string rather than undefined, so JSON.stringify keeps it and
it is sent as though it were a genuine URL.

ci_env() enters this branch on GITHUB_RUN_NUMBER alone, so the other two
variables are not guaranteed. The existing test 'uses github action
environment variables second' already exercises this exact path — it sets
only GITHUB_RUN_NUMBER — but asserts only on ci.

buildkite() and circleci() are unaffected: they assign process.env values
directly, so a missing variable stays undefined and JSON.stringify drops the
key. This brings github_actions() in line with them.

Same defect as buildkite/test-collector-python#132.

Adds a regression test that fails on the current code and passes with the
change.

…kite/test-collector-python#132)

_github_actions_env builds the URL with an f-string over two values that
_get_env can legitimately return as None. When either is missing, the
interpolation produces the literal string 'None' inside the URL:

    https://github.com/None/actions/runs/None

That value is then a non-None string, so as_json() keeps it and sends it to
the API instead of omitting the field.

The other two CI branches do not have this problem. _buildkite_env and
_circle_ci_env pass _get_env(...) straight through, so a missing value stays
None and as_json() filters it out. This brings the GitHub Actions branch in
line with them.

The guard clause above only requires GITHUB_ACTION, GITHUB_RUN_NUMBER and
GITHUB_RUN_ATTEMPT, so reaching this code with either of the other two unset
is possible — most plausibly through RunEnvBuilder's documented injected
environment, or a runner with a trimmed environment.

Adds a regression test that fails on the current code with the 'None' URL and
passes with the change.

Co-authored-by: SirHegel <SirHegel@users.noreply.github.com>

github_actions() builds the URL with a template literal over two environment
variables that may be undefined. Interpolating undefined yields the literal
string 'undefined', so the result is:

    https://github.com/undefined/actions/runs/undefined

That is a real string rather than undefined, so JSON.stringify keeps it and
it is sent as though it were a genuine URL.

ci_env() enters this branch on GITHUB_RUN_NUMBER alone, so the other two
variables are not guaranteed. The existing test 'uses github action
environment variables second' already exercises this exact path — it sets
only GITHUB_RUN_NUMBER — but asserts only on ci.

buildkite() and circleci() are unaffected: they assign process.env values
directly, so a missing variable stays undefined and JSON.stringify drops the
key. This brings github_actions() in line with them.

Same defect as buildkite/test-collector-python#132.

Adds a regression test that fails on the current code and passes with the
change.