x2t: move overrides to package.nix - #485680

       > kill machine (pid 9)
       > qemu-system-aarch64: terminating on signal 15 from pid 6 (/nix/store/ygzfhw5nxrn7qqfqmz2s9p6cikcjqqkh-python3-3.13.11/bin/python3.13)
       > vde_switch: EOF data port: Interrupted system call
       > kill vlan (pid 7)
       > vde_switch: EOF on stdin, cleaning up and exiting
       >
       > vde_switch: Caught signal 15, cleaning up and exiting
       > (finished: cleanup, in 0.01 seconds)
       For full logs, run:
         nix log /nix/store/vpcb07952jmdraj4ym3rg17sja194kw5-vm-test-run-onlyoffice.drv