Fix buildMigrationNamespaceResolver to use isValidSuffix(...) instead of hard-coded check

src/orm/services/Migrations.ts

@@ -67,7 +67,7 @@ export class Migrations extends CanonicalInstantiable<Migration> {
         const namespace: {[key: string]: Migration} = {}
 
         for await ( const entry of basePath.walk() ) {
-            if ( !entry.endsWith(this.suffix) ) {
+            if ( !this.isValidSuffix(entry) ) {
                 this.logging.debug(`buildMigrationNamespaceResolver - Skipping file with invalid suffix: ${entry}`)
                 continue
             }