fix: constructor ahead of deprecated

Author: joelgallant

app-config-node/src/file-source.ts

@@ -53,6 +53,8 @@ export class FlexibleFileSource extends ConfigSource {
   private readonly fileExtensions: string[];
   private readonly environmentOptions: EnvironmentOptions;
 
+  constructor(filePath: string, fileExtensions?: string[], environmentOptions?: EnvironmentOptions);
+
   /** @deprecated use constructor with environmentOptions instead */
   constructor(
     filePath: string,
@@ -62,8 +64,6 @@ export class FlexibleFileSource extends ConfigSource {
     environmentSourceNames?: string[] | string,
   );
 
-  constructor(filePath: string, fileExtensions?: string[], environmentOptions?: EnvironmentOptions);
-
   constructor(
     filePath: string,
     environmentOverrideOrFileExtensions?: string | string[],