Deprecation warnings with PHP 8.2

Problem/Motivation

After installing the silktide module I am presented with the following deprecation warnings. This is using Drupal 10 with PHP 8.2 and before setting the API key.

Deprecated function: openssl_encrypt(): Passing null to parameter #3 ($passphrase) of type string is deprecated in silktide_page_attachments() (line 107 of modules/contrib/silktide/silktide.module).

Deprecated function: hash_hmac(): Passing null to parameter #3 ($key) of type string is deprecated in silktide_page_attachments() (line 119 of modules/contrib/silktide/silktide.module).

Steps to reproduce

Install the silktide module on a development environment with deprecation warnings showing and no silktide API key set.

Proposed resolution

In `silktide_page_attachments` check that the API key is set/not empty before continuing.

Remaining tasks

User interface changes

API changes

Data model changes