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.

.github/workflows/release.yml

@@ -428,7 +428,7 @@ jobs:
           node -e "
             const fs = require('fs');
             const pkg = JSON.parse(fs.readFileSync('package.json'));
-            pkg.author = 'kingchenc <wickra.lib@gmail.com>';
+            pkg.author = 'kingchenc <support@wickra.org>';
             pkg.repository = { type: 'git', url: 'https://github.com/wickra-lib/wickra' };
             pkg.homepage = 'https://github.com/wickra-lib/wickra';
             pkg.bugs = { url: 'https://github.com/wickra-lib/wickra/issues' };