[Snek] [keith-packard/snek] 069e8c: Update qemu version to match custom version

[Keith Packard]

  Branch: refs/heads/main
  Home:   https://github.com/keith-packard/snek
  Commit: 069e8c9f4c73e07c34b38844bcf06527aae1033c
      https://github.com/keith-packard/snek/commit/069e8c9f4c73e07c34b38844bcf06527aae1033c
  Author: Keith Packard <keithp at keithp.com>
  Date:   2020-06-04 (Thu, 04 Jun 2020)

  Changed paths:
    M .github/Dockerfile

  Log Message:
  -----------
  Update qemu version to match custom version

We're using a custom qemu image to support testing on risc-v.

Signed-off-by: Keith Packard <keithp at keithp.com>