Require dynamicprompts 0.31.0

This should resolve https://github.com/adieyal/sd-dynamic-prompts/issues/743 via https://github.com/adieyal/dynamicprompts/pull/122 and also enables the [other new things in dp 0.31.0](https://github.com/adieyal/dynamicprompts/releases/tag/v0.31.0): * Wrap command: https://github.com/adieyal/dynamicprompts/pull/102 * Support Preserving Variable Values: https://github.com/adieyal/dynamicprompts/pull/115 * Dynamic Wildcards: https://github.com/adieyal/dynamicprompts/pull/114 * Single-string collections: https://github.com/adieyal/dynamicprompts/pull/113