fix(watch): preserve ProcState::file_fetcher between restarts (#15466)

This commit changes "ProcState" to store "file_fetcher" field in an "Arc",
allowing it to be preserved between restarts and thus keeping the state
alive between the restarts. File watchers for "deno test" and "deno bench"
now reset "ProcState" between restarts.

cli/module_loader.rs

@@ -277,7 +277,6 @@ impl ModuleLoader for CliModuleLoader {
         lib,
         root_permissions,
         dynamic_permissions,
-        false,
       )
       .await
     }