Closes #47303 

The command quoting for `cmd` shell was first introduced (at least in
this case) in PR #41216 three months ago:

https://github.com/zed-industries/zed/blob/3d4582d4dc9145270650e12f9ce5a534b888f4a2/crates/project/src/terminals.rs#L202-L210

And a month ago, PR #42382 added command quoting for `cmd` in a
different place:

https://github.com/zed-industries/zed/blob/3d4582d4dc9145270650e12f9ce5a534b888f4a2/crates/util/src/shell.rs#L413-L434

As a result, the command is now quoted twice when using `cmd`. `cmd`
interprets the entire double-quoted string (e.g., ""command & args"") as
a single (invalid) executable name, and this would lead to an error like
“The system cannot find the path specified” in #47303 .

The solution is to remove the redundant manual quoting in `terminals.rs`
and rely on the centralized logic in `util/src/shell.rs`.

/cc @Veykril @reflectronic 

Release Notes:

- Fixed a bug where terminal tasks failed to start on Windows when using
`cmd.exe`.