13521: `<Say>` element character limits exceeded

The maximum text length inside a verb is limited and varies depending on the option used. Basic, Polly and Google TTS have different limits and character count.
See the Say Verb API Reference for more information.

The maximum text length inside the <Say> verb has been exceeded.

Make sure that the character limit is under the limit for the TTS type being used:

• Basic TTS Voices are limited to 4096 UTF-8 single byte characters
• Polly TTS Voices are limited to 3000 UTF-8 single byte characters; note that SSML tags do not contribute to the character count
• Google TTS Voices are limited to 5000 UTF-8 single byte characters; note that SSML tags, newlines and spaces contribute to the character count
• The URL-encoded string cannot exceed 4500 characters