Alerting: Set isNoData if isCondNoData

[grobinson-grafana]

What this PR does / why we need it:

In the original ConditionsCmd code No Data was set to true if thisCondNoData, even if the outcome of the || or && comparison was false.

if c.Operator == "or" {
	firing = firing || thisCondFiring
	noDataFound = noDataFound || thisCondNoData
} else {
	firing = firing && thisCondFiring
	noDataFound = noDataFound && thisCondNoData
}

if thisCondNoData {
	matches = append(matches, EvalMatch{
		Metric: "NoData",
	})
        // noDataFound is set to true here
	noDataFound = true
}

This line appears to be significant in maintaining the current behaviour of ConditionsCmd and was omitted from #56812.

Which issue(s) does this PR fix?:

Fixes #55085

Special notes for your reviewer:

[grobinson-grafana]

No backport because I have decided not to backport #56812.

[grafanabot]

Drone build failed: https://drone.grafana.net/grafana/grafana-enterprise/41348