fix: npm releases failing to generate provenance (#3800) (#3801)

# Backport

This will backport the following commits from `k8s-28/main` to `k8s-26/main`:
 - [fix: npm releases failing to generate provenance (#3800)](#3800)



### Questions ?
Please refer to the [Backport tool documentation](https://github.com/sqren/backport)

.projenrc.ts

@@ -72,6 +72,10 @@ const project = new Cdk8sTeamJsiiProject({
 // Used in K8s upgrade tests to control publishing of new branches
 project.package.addField('private', false);
 
+// not using `npmAccess` property because projen omits values that are
+// identical to npm defaults.
+project.package.addField('publishConfig', { access: 'public' });
+
 project.gitignore.exclude('.vscode/');
 
 const importdir = path.join('src', 'imports');