JS-1609 Clean up accepted S4204/S3801 issues in SonarJS self-analysis (#6843)

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: guillemsarda

packages/analysis/src/jsts/rules/S100/rule.ts

@@ -131,5 +131,5 @@ export const rule: Rule.RuleModule = {
 
 //handling arrow functions without return statement
 function returnsJSX(node: estree.Function) {
-  return (node.body as any).type.startsWith('JSX');
+  return node.body.type.startsWith('JSX');
 }

packages/analysis/src/jsts/rules/S109/rule.ts

@@ -80,9 +80,7 @@ function getNumericLiteral(node: estree.Literal) {
 }
 
 function numericLiteralValue(node: estree.Literal) {
-  if (typeof node.value === 'number') {
-    return node.value;
-  }
+  return typeof node.value === 'number' ? node.value : undefined;
 }
 
 function isNumericLiteral(node: estree.Node): node is estree.Literal {

packages/analysis/src/jsts/rules/S1105/decorator.ts

@@ -35,7 +35,7 @@ function reportExempting(
   exemptionCondition: (messageId: string) => boolean,
 ): (context: Rule.RuleContext, reportDescriptor: Rule.ReportDescriptor) => void {
   return (context, reportDescriptor) => {
-    if (exemptionCondition((reportDescriptor as any).messageId)) {
+    if ('messageId' in reportDescriptor && exemptionCondition(reportDescriptor.messageId)) {
       context.report(reportDescriptor);
     }
   };