Everywhere: Use LibFileSystem where trivial

Author: https://github.com/cammo1123
Commit: 1d24f394c6
Pull-request: https://github.com/SerenityOS/serenity/pull/17789
Reviewed-by: https://github.com/AtkinsSJ
Reviewed-by: https://github.com/caoimhebyrne
Reviewed-by: https://github.com/kleinesfilmroellchen ✅
Reviewed-by: https://github.com/linusg
Reviewed-by: https://github.com/pascalpuffke
Reviewed-by: https://github.com/timschumi ✅

Meta/Lagom/Tools/ConfigureComponents/main.cpp

@@ -13,6 +13,7 @@
 #include <AK/Vector.h>
 #include <LibCore/ConfigFile.h>
 #include <LibCore/DeprecatedFile.h>
+#include <LibFileSystem/FileSystem.h>
 #include <spawn.h>
 #include <sys/ioctl.h>
 #include <sys/wait.h>
@@ -241,7 +242,7 @@ int main()
         return 1;
     }
 
-    if (!Core::DeprecatedFile::exists("components.ini"sv)) {
+    if (!FileSystem::exists("components.ini"sv)) {
         warnln("\e[31mError:\e[0m There is no 'components.ini' in the current working directory.");
         warnln("       It can be generated by running CMake with 'cmake ../.. -G Ninja'");
         return 1;