Fix code scanning alert no. 280: Disallow the any type

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: tolauwae

src/sourcemap/SourceMapper.ts

@@ -34,7 +34,7 @@ export class WatMapper implements SourceMapper {
             let imports: Closure[];
             let sourceMap: Mapping;
 
-            function handleObjDumpStreams(error: ExecException | null, stdout: string, stderr: any) {
+            function handleObjDumpStreams(error: ExecException | null, stdout: string, stderr: string) {
                 if (stderr.match('wasm-objdump')) {
                     reject('Could not find wasm-objdump in the path');
                 } else if (error) {