Bump tokentoll action SHA pin to v0.6.0

v0.6.0 adds a ZhipuDetector (so Zhipu/GLM calls are attributed
correctly) and a constructor-call fallback for OpenAI/Anthropic
detectors, recovering DI-style detections that the v0.5.2 strict
import check had dropped.

Author: Jwrede

.github/workflows/llm-costs.yml

@@ -15,4 +15,4 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: Jwrede/tokentoll@cfc9307c2e820de1223fc707ee7e945f6f972379  # v0.5.2
+      - uses: Jwrede/tokentoll@ff50a35604b7858d9064cca6354b6229a94f7235  # v0.6.0