Mistral Instruct LLM doesn#t use chat template

In the implementation of the mistral LLM connection an attribute is created which checks if the Instruct model version was selected. This check fails, as it is checked if lowercase "instruct" is in the model name. However, it should be checked for "Instruct", otherwise the attribute is always false and the wrong chat template is used.

## Info about spaCy

- **spaCy version:** 3.7.4
- **Platform:** Linux-6.5.13-1-pve-x86_64-with-glibc2.35
- **Python version:** 3.10.12