chore: remove the unused flyfish file viewer static files

删除了项目中未使用的flyfish文件查看器相关的所有静态资源文件，包括各类资源脚本、样式、wasm模块和配置文件等，清理冗余代码和资源。

ruoyi-ui/public/file-viewer/_headers

@@ -1,22 +0,0 @@
-/*
-  X-Content-Type-Options: nosniff
-  Referrer-Policy: strict-origin-when-cross-origin
-
-/*.html
-  Cache-Control: public, max-age=0, must-revalidate
-
-/assets/*
-  Cache-Control: public, max-age=31536000, immutable
-
-/vendor/*
-  Cache-Control: public, max-age=31536000, immutable
-
-/wasm/*
-  Cache-Control: public, max-age=31536000, immutable
-  X-Content-Type-Options: nosniff
-
-/wasm/*.wasm
-  Content-Type: application/wasm
-
-/example/*
-  Cache-Control: public, max-age=86400