Bump azure-monitor-opentelemetry-exporter in /code/function

Bumps [azure-monitor-opentelemetry-exporter](https://github.com/Azure/azure-sdk-for-python) from 1.0.0b17 to 1.0.0b18.
- [Release notes](https://github.com/Azure/azure-sdk-for-python/releases)
- [Changelog](https://github.com/Azure/azure-sdk-for-python/blob/main/doc/esrp_release.md)
- [Commits](Azure/azure-sdk-for-python@azure-monitor-opentelemetry-exporter_1.0.0b17...azure-monitor-opentelemetry-exporter_1.0.0b18)

---
updated-dependencies:
- dependency-name: azure-monitor-opentelemetry-exporter
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

code/function/requirements.txt

@@ -8,4 +8,4 @@ fastapi~=0.104.1
 pydantic-settings~=2.0.3
 aiohttp~=3.8.6
 opentelemetry-instrumentation-fastapi==0.41b0
-azure-monitor-opentelemetry-exporter==1.0.0b17
+azure-monitor-opentelemetry-exporter==1.0.0b18