ci: avoid ANSI C-Quoting

While `bash` and other shells support it, `dash` (`/bin/sh` in Ubuntu)
does not, and it is better to avoid Bash-dependent behaviors anyway.

In particular, GitHub Actions, when using a container, does not attempt
to force `bash`, thus we can simply use `dash` instead.

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

.github/workflows/ci.yaml

@@ -338,7 +338,7 @@ jobs:
               rust_module_parameters_builtin_custom.my_usize=84 \
               rust_module_parameters_builtin_custom.my_array=1,2,3 \
             ' \
-            | sed s:$'\r'$:: \
+            | sed 's:\r$::' \
             | tee qemu-stdout.log
 
       # The kernel should not be generating any warnings