[vvoytovych]

Related to #978.

The required check, ci / Build and test, runs go test ./... with envtest 1.37.0 on every pull request and on main. "IAM API testing" ran the same go test ./... on every push that changed Go files. It is not required, so it gated nothing, and each pull request ran the suite twice. It goes, as datum-cloud/network-services-operator#849 did for NSO, and CI takes the concurrency group the other workflows share.

Where each step of IAM API testing runs now

step	where
go mod download	CI: go test downloads what it needs
envtest 1.37.0	CI: setup-envtest use 1.37.0, pinned by commit
go test ./...	CI, with a 10 min timeout instead of 5

Corner cases

case	what happens
A push to a branch with no pull request	No suite run until its pull request opens. Milo has no release branches; it releases by tag from main.
A newer push to a pull request	The older CI run is cancelled.
A push to main	Its run is never cancelled: cancel-in-progress is false on the default branch.

Test plan

• ci / Build and test ran the suite on fix: Decide a claim's requests of one type together #978's pull request and on this one: the quota controller package's envtests took 51.7 s and 52.3 s.
• actionlint passes on ci.yaml. The concurrency group is the one in fix-newlines.yaml, test-environment-validation.yaml and test-prometheus-rules.yaml, word for word.
• Nothing in the repository names testing.yaml or "IAM API testing".
• After the merge: the push to main ran CI's suite (run, the quota controller package in 52.6 s), and "IAM API testing" did not run.

[ecv]

Approve.

"IAM API testing" ran the same go test ./... with envtest 1.37.0 that the required ci / Build and test already runs (ci.yaml installs setup-envtest, uses 1.37.0, and runs go test ./... -timeout 10m), so deleting it removes a duplicate run without dropping coverage. ci / Build and test stays the only check the required-ci ruleset names, so no gate disappears.

• ci.yaml gains the same concurrency group the deleted workflow had: pull-request and branch runs cancel superseded ones, main runs never cancel.
• The deleted job ran on every push that touched Go, including branches without a PR; those now get a run only once a PR is opened, which is where the gate is.

Follow-ups:

• The deleted job had a 5-minute test timeout against ci.yaml's 10; a suite that drifts past 5 minutes will no longer be noticed early. Fine, but worth knowing if test time is watched.

[vvoytovych]

On the timeout: go test -timeout bounds each package's test binary, not the whole suite. The slowest package, internal/controllers/iam, took 81.8 s on this pull request's run, so it is far from 5 minutes and from 10. The deleted job's test step took about 8 minutes on main under the 5-minute bound, so that bound never measured the suite. ci.yaml already had 10 minutes, and I left it as it was.