Revert the change to parseErrorAtPosition in parser.ts

The change is no longer necessary since it’s moved to `checker.ts` in microsoft#58295.

The partially reverts microsoft@1a5228d.

src/compiler/parser.ts

@@ -62,7 +62,6 @@ import {
     DeleteExpression,
     Diagnostic,
     DiagnosticArguments,
-    DiagnosticCategory,
     DiagnosticMessage,
     Diagnostics,
     DiagnosticWithDetachedLocation,
@@ -2144,11 +2143,7 @@ namespace Parser {
         // Don't report another error if it would just be at the same position as the last error.
         const lastError = lastOrUndefined(parseDiagnostics);
         let result: DiagnosticWithDetachedLocation | undefined;
-        if (message.category === DiagnosticCategory.Message && lastError && start === lastError.start && length === lastError.length) {
-            result = createDetachedDiagnostic(fileName, sourceText, start, length, message, ...args);
-            addRelatedInfo(lastError, result);
-        }
-        else if (!lastError || start !== lastError.start) {
+        if (!lastError || start !== lastError.start) {
             result = createDetachedDiagnostic(fileName, sourceText, start, length, message, ...args);
             parseDiagnostics.push(result);
         }