[chore]: enable negative-positive rule from testifylint (#35046)

#### Description

Testifylint is a linter that provides best practices with the use of
testify.

This PR enables
[negative-positive](https://github.com/Antonboom/testifylint?tab=readme-ov-file#negative-positive)
rule from [testifylint](https://github.com/Antonboom/testifylint)

Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>

unstructured_to_logdata_test.go

@@ -165,7 +165,7 @@ func TestUnstructuredListToLogData(t *testing.T) {
 		logRecords := rl.ScopeLogs().At(0).LogRecords()
 		assert.Equal(t, 1, rl.ScopeLogs().Len())
 		assert.Equal(t, 1, logRecords.Len())
-		assert.Greater(t, logRecords.At(0).ObservedTimestamp().AsTime().Unix(), int64(0))
+		assert.Positive(t, logRecords.At(0).ObservedTimestamp().AsTime().Unix())
 		assert.Equal(t, logRecords.At(0).ObservedTimestamp().AsTime().Unix(), observedAt.Unix())
 	})