Stop returning NOTCAPABLE errors from WASI calls. (#4666)

* Stop returning `NOTCAPABLE` errors from WASI calls.

`ENOTCAPABLE` was an error code that is used as part of the rights
system, from CloudABI. There is a set of flags associated with each file
descriptor listing which operations can be performed with the file
descriptor, and if an attempt is made to perform an operation with a
file descriptor that isn't permitted by its rights flags, it fails with
`ENOTCAPABLE`.

WASI is removing the rights system. For example, WebAssembly/wasi-libc#294
removed support for translating `ENOTCAPABLE` into POSIX error codes, on
the assumption that engines should stop using it.

So as another step to migrating away from the rights system, remove uses
of the `ENOTCAPABLE` error.

* Update crates/wasi-common/src/file.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

* Update crates/wasi-common/src/dir.rs

Co-authored-by: Jamey Sharp <jamey@minilop.net>

Co-authored-by: Jamey Sharp <jamey@minilop.net>

crates/wasi-common/src/snapshots/preview_1.rs

@@ -84,6 +84,7 @@ impl From<ErrorKind> for types::Errno {
             ErrorKind::Range => Errno::Range,
             ErrorKind::Spipe => Errno::Spipe,
             ErrorKind::NotCapable => Errno::Notcapable,
+            ErrorKind::Perm => Errno::Perm,
         }
     }
 }