fix: the diff processor should not hide typecheck errors

Author: ldez

pkg/result/processors/diff.go

@@ -65,6 +65,11 @@ func (p Diff) Process(issues []result.Issue) ([]result.Issue, error) {
 	}
 
 	return transformIssues(issues, func(issue *result.Issue) *result.Issue {
+		if issue.FromLinter == "typecheck" {
+			// Never hide typechecking errors.
+			return issue
+		}
+
 		hunkPos, isNew := c.IsNewIssue(issue)
 		if !isNew {
 			return nil