swap: try to make swapfile working on btrfs

Since F35, the swap service started failing with:

    kernel: BTRFS warning (device nvme0n1p5): swapfile must not be copy-on-write
    swapon[2976986]: swapon: /swap: swapon failed: Invalid argument
    swap.swap: Swap process exited, code=exited, status=255/EXCEPTION

tasks/swap.yml

@@ -2,6 +2,15 @@
 #   swap_file_size_mb
 #   swap_file_path
 
+- name: Touch an empty file that we will use for swap
+  file:
+    path: "{{ swap_file_path }}"
+    state: touch
+
+- name: On BTRFS we need NoCOW
+  file: path="{{ swap_file_path }}"
+  attr: +C
+
 - name: Create swap file
   command:
     cmd: "dd if=/dev/zero of={{ swap_file_path }} bs=1024 count={{ swap_file_size_mb }}k"