Remove LLM-benchmark timeout (#5458)

# Description of Changes

Periodic LLM benchmark jobs can take more than 3 hour, this PR remove
the 3 hour limit in favor of Github's default to 6 hours

# API and ABI breaking changes

None

# Expected complexity level and risk

1

# Testing

Not tested, I need to merge to be able to test as it is a CI change

---------

Signed-off-by: Julien Lavocat <JulienLavocat@users.noreply.github.com>
Co-authored-by: Zeke Foppa <196249+bfops@users.noreply.github.com>

Author: JulienLavocat

.github/workflows/llm-benchmark-periodic.yml

@@ -50,7 +50,6 @@ concurrency:
 jobs:
   run-benchmarks:
     runs-on: spacetimedb-new-runner-2
-    timeout-minutes: 180
 
     steps:
       - name: Checkout repository