fs: drop old WSL1 hack.

src/fs.cpp

@@ -60,27 +60,12 @@ FileLock::~FileLock()
     }
 }
 
-static bool IsWSL()
-{
-    struct utsname uname_data;
-    return uname(&uname_data) == 0 && std::string(uname_data.version).find("Microsoft") != std::string::npos;
-}
-
 bool FileLock::TryLock()
 {
     if (fd == -1) {
         return false;
     }
 
-    // Exclusive file locking is broken on WSL using fcntl (issue #18622)
-    // This workaround can be removed once the bug on WSL is fixed
-    static const bool is_wsl = IsWSL();
-    if (is_wsl) {
-        if (flock(fd, LOCK_EX | LOCK_NB) == -1) {
-            reason = GetErrorReason();
-            return false;
-        }
-    } else {
     struct flock lock;
     lock.l_type = F_WRLCK;
     lock.l_whence = SEEK_SET;
@@ -90,7 +75,6 @@ bool FileLock::TryLock()
         reason = GetErrorReason();
         return false;
     }
-    }
 
     return true;
 }