Say that the zizmor absence outlives the empty required set (#26)

internal/contexts/contexts.go

@@ -140,7 +140,12 @@ var Absences = []Absence{
 	{Name: "format", Why: theSetIsEmpty, Until: "#26"},
 	{Name: "CodeQL (go)", Why: theSetIsEmpty, Until: "#26"},
 	{Name: "CodeQL", Why: theSetIsEmpty, Until: "#26"},
-	{Name: "zizmor", Why: theSetIsEmpty, Until: "#26"},
+	{
+		Name: "zizmor",
+		Why: "this name is created by the code-scanning upload in zizmor.yml rather than by the job, and that step is skipped wherever the token cannot write security events, so requiring it would hold open every pull request the condition excludes with nothing on the pull request saying why. " +
+			"The job reports under Audit workflows (zizmor), which is a different string, arrives on those pull requests and carries the step that fails on findings",
+		Until: "",
+	},
 	{Name: "DCO sign-off", Why: theSetIsEmpty, Until: "#26"},
 	{Name: "dependency-review", Why: theSetIsEmpty, Until: "#26"},
 	{Name: "headless and unelevated", Why: theSetIsEmpty, Until: "#26"},

internal/contexts/contexts_test.go

@@ -279,6 +279,26 @@ func TestAnAbsenceCarriesAReason(t *testing.T) {
 	}
 }
 
+// TestAPermanentAbsenceDoesNotRestOnAReasonThatEnds refuses an entry that says
+// its absence is permanent and gives the reason that stops being true first.
+//
+// The two fields are read together. An empty Until says the absence survives the
+// day the required set is assembled, and theSetIsEmpty says the name is outside
+// the set because the set has no members, which is exactly the condition that day
+// ends. An entry carrying both is a decision resting on a debt, and it reads as
+// settled to whoever assembles the set.
+//
+// The near-miss this is written for is one field: an absence whose reason turns
+// out to be its own rather than the shared one is made permanent by emptying
+// Until, and the reason above it is left as it was.
+func TestAPermanentAbsenceDoesNotRestOnAReasonThatEnds(t *testing.T) {
+	for _, absence := range Absences {
+		if absence.Until == "" && absence.Why == theSetIsEmpty {
+			t.Errorf("the absence %q is written as permanent and its reason is that the required set is empty, which is the condition that ends when the set is assembled, so the entry says the absence outlives the only thing it rests on", absence.Name)
+		}
+	}
+}
+
 // TestAJobWithNoNameOfItsOwnIsNotedRatherThanRefused pins the one place this
 // package answers with a note. The platform reports the job id where a job
 // carries no name, so such a job is legal and its name is still a gate string, and