fix: Fix CI test_function_call_parser.py

[CatherineSue]

Motivation

• Fix CI
• If there is already a tool, the next token can be simply a tool_call_separator, before following with a {.
• This check was originally covered in L114, but it was changed in bec5891 then the CI failed

Modifications

Checklist

• Format your code according to the Code Formatting with Pre-Commit.
• Add unit tests as outlined in the Running Unit Tests.
• Update documentation / docstrings / example tutorials as needed, according to Writing Documentation.
• Provide throughput / latency benchmark results and accuracy evaluation results as needed, according to Benchmark and Profiling and Accuracy Results.
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