Account for typed code block responses from the LLM
What does this MR do and why?
There have been occasional reports of RTV failing. After a tedious bit of testing for curiosities sake, this turned out to be caused by the LLM providing a type in it's diff block.
We expected something like the following:
```
the_new(function_call: here)
```
The LLM, only in some contexts would return this:
```java
the_new(function_call: here)
```
This MR changes the regex to account for this possibility.
MR acceptance checklist
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How to set up and validate locally
Validation is troublesome as it requires testing a specific vulnerability that resulted in a LLM response like this. I was able to replicate this by locally cloning the repo referred to in this comment thread: #435721 (comment 1760915408)
Related to #437686