[Bug] new support for Python f-strings breaks with multi-line f-strings

Reproducible in vscode.dev or in VS Code Desktop?

• Not reproducible in vscode.dev or VS Code Desktop

Reproducible in the monaco editor playground?

• Not reproducible in the monaco editor playground

Monaco Editor Playground Link

Link

Monaco Editor Playground Code

single_line_f_string f'''nothing {'to see'} here'''

multi_line_f_string = f"""first line looks fine
{'uh oh'}
now the highlighting is broken down here :(
"""

also = "it's broken highlighting for everything after"
four = 2 + 2

Reproduction Steps

1. Configure an editor using the built-in python language
2. Enter a multi-line f-string which has an expression after the 1st line

Actual (Problematic) Behavior

The portion of the f-string after the expression is highlighted as python code instead of a string, and then the closing f-string delimiter causes code after that to be highlighted as if it were a string

Expected Behavior

Self evident

Additional Context

I believe this was added with #4401, which notably does not have multi-line f-strings in its test coverage.

Start with the linked Monaco Editor playground reproduction and inspect the f-string support and test coverage introduced by #4401, which does not cover multiline f-strings. Reproduce an expression after the first line of a multiline f-string; done when the remaining string stays highlighted as a string and code after the closing delimiter returns to normal Python highlighting.