chore: use support@wickra.org for contact/author email; drop dead sponsor link (#97)

Now that the wickra.org catch-all mailbox exists, move the project contact +
package-author email off the personal gmail to support@wickra.org across all
surfaces: CODE_OF_CONDUCT, SECURITY, CITATION.cff, Cargo.toml, the npm + PyPI
author fields, the release.yml npm author, and repo-metadata.toml. (The
package-author changes take effect on the next published release.)

repo-metadata.toml's [audit].forbidden still pins kingchencp@gmail.com (the
private commit email) as a banned substring — unchanged.

Also remove the FUNDING.yml custom "https://wickra.org/sponsor" entry: that
page 404s, so the Sponsor button linked to a dead URL. The GitHub Sponsors
entry (github: [kingchenc]) stays.

Cargo.toml

@@ -13,7 +13,7 @@ exclude = ["fuzz"]
 
 [workspace.package]
 version = "0.3.1"
-authors = ["kingchenc <wickra.lib@gmail.com>"]
+authors = ["kingchenc <support@wickra.org>"]
 edition = "2021"
 rust-version = "1.86"
 license = "PolyForm-Noncommercial-1.0.0"