fix(tools): fix type errors in create-element template

[martinpitt]

Commit c9bd577 enabled isolatedDeclarations, which introduced these errors in npm new generated components:

TS9008: Method must have an explicit return type annotation with --isolatedDeclarations.
render() {

TS9017: Only const arrays can be inferred with --isolatedDeclarations.
static readonly styles = [styles];

Fixes #2872

---

Testing Instructions

See #2872. Tested with

npm run new  # name it "pf-cool" or anything else
npm start

[changeset-bot]

⚠️ No Changeset found

Latest commit: b27da42

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[github-actions]

✅ Commitlint tests passed!

More Info

{
  "valid": true,
  "errors": [],
  "warnings": [],
  "input": "fix(tools): fix type errors in create-element template"
}

[netlify]

✅ Deploy Preview for patternfly-elements ready!

Name	Link
🔨 Latest commit	7f8abd9
🔍 Latest deploy log	https://app.netlify.com/sites/patternfly-elements/deploys/6730555dcb037c0008a67820
😎 Deploy Preview	https://deploy-preview-2873--patternfly-elements.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[bennypowers]

Just needed a changeset and a fix to package.json

Nice work, and thank you for the contribution!