fix(task): support backticks and basic tilde expansion (#28832)
* https://github.com/denoland/deno_task_shell/pull/147
* https://github.com/denoland/deno_task_shell/pull/146
Closes https://github.com/denoland/deno/issues/26676
Closes https://github.com/denoland/deno/issues/28807
