Cargo.toml: Define feat_wasm

[oech3]

Closes #10928 (and publish them).

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/date/resolution. tests/date/resolution is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/cut/bounded-memory is no longer failing!
Congrats! The gnu test tests/date/date-locale-hour is no longer failing!
Skip an intermittent issue tests/pr/bounded-memory (was skipped on 'main', now failing)