chore(github): emit event when API rate limit exceeded

Add Kubernetes event emission via EmitMessage when GitHub API rate
limit remaining hits zero. This surfaces rate limit exhaustion as
a Repository event, improving observability for operators.

Signed-off-by: Akshay Pant <akpant@redhat.com>

Author: theakshaypant

pkg/provider/github/profiler.go

@@ -8,10 +8,12 @@ import (
 
 	"github.com/google/go-github/v85/github"
 	providerMetrics "github.com/openshift-pipelines/pipelines-as-code/pkg/provider/providermetrics"
+	"go.uber.org/zap"
 )
 
 const (
 	// Rate limit warning thresholds.
+	rateLimitExceeded = 0   // Error when remaining calls are 0
 	rateLimitCritical = 50  // Warn when remaining calls < 50
 	rateLimitWarning  = 100 // Warn when remaining calls < 100
 	rateLimitInfo     = 500 // Info when remaining calls < 500
@@ -69,6 +71,13 @@ func (v *Provider) checkRateLimit(resp *github.Response) (remaining string) {
 		"reset", reset,
 	}
 	switch {
+	case remainingCount == rateLimitExceeded:
+		v.Logger.Errorw("GitHub API rate limit exceeded", logFields...)
+		if v.eventEmitter != nil {
+			v.eventEmitter.EmitMessage(
+				v.repo, zap.ErrorLevel, "GitHubRateLimitExceeded",
+				fmt.Sprintf("GitHub API rate limit exceeded, limit: %s, resets at: %s", limit, reset))
+		}
 	case remainingCount < rateLimitCritical:
 		v.Logger.Errorw("GitHub API rate limit critically low", logFields...)
 	case remainingCount < rateLimitWarning: