Commit signing doesn't work with non-RSA keys

[thusoy]

Describe the bug
When setting gpg_private_key to a non-RSA key, it fails to be picked up by the action since it only searches for the rsa\d+ prefix of the key. The key type is filtered here.

To Reproduce
Steps to reproduce the behavior:

1. Create a gpg key with ed25519 or nistp384 key types and add to repo secrets.
2. Include this in your workflow:

- name: Download translations from Crowdin
        uses: crowdin/github-action@v2
        with:
          upload_sources: false
          download_translations: true
          create_pull_request: true
          gpg_private_key: ${{ secrets.CI_USER_CROWDIN_GPG_KEY }}
          gpg_passphrase: '' # Not encrypted, passphrase would be distributed the same way as the key so doesn't add any practical benefits
          github_user_name: some name
          github_user_email: email that matches key
        env:
          CROWDIN_PERSONAL_TOKEN: ${{ secrets.CROWDIN_PERSONAL_TOKEN }}
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Expected behavior
Commit signing works.

Additional context
This is the error output:

FOUND PRIVATE KEY, WILL SETUP GPG KEYSTORE
gpg: directory '/github/home/.gnupg' created
gpg: /github/home/.gnupg/trustdb.gpg: trustdb created
gpg: key 7852AE445F33F9D6: public key "<ci and email>" imported
gpg: key 7852AE445F33F9D6: secret key imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg:       secret keys read: 1
gpg:   secret keys imported: 1
Imported key information:
      Key id: 
  Owner name: <ci name>
 Owner email: <ci-email>
CONFIGURING GIT USER
M	<file-path-removed>
Already on 'crowdin-gpg-key'
<files-changed-removed>
Your branch is up to date with 'origin/crowdin-gpg-key'.
Switched to a new branch 'l10n_crowdin_action'
PUSH TO BRANCH l10n_crowdin_action
error: gpg failed to sign the data:
gpg: skipped "": Invalid user ID
[GNUPG:] INV_SGNR 0 
[GNUPG:] FAILURE sign 37
gpg: signing failed: Invalid user ID

fatal: failed to write commit object