Bump azure-storage-blob from 12.14.1 to 12.15.0 (#1357)

Bumps [azure-storage-blob](https://github.com/Azure/azure-sdk-for-python) from 12.14.1 to 12.15.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-python/releases)
- [Commits](Azure/azure-sdk-for-python@azure-storage-blob_12.14.1...azure-storage-blob_12.15.0)

---
updated-dependencies:
- dependency-name: azure-storage-blob
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements_dev_optional.txt

@@ -7,7 +7,7 @@ ipywidgets==8.0.4
 # optional library requirements for services
 # don't let pyup change pinning for azure-storage-blob, need to pin to older
 # version to get compatibility with azure storage emulator on appveyor (FIXME)
-azure-storage-blob==12.14.1 # pyup: ignore
+azure-storage-blob==12.15.0 # pyup: ignore
 redis==4.5.1
 types-redis
 types-setuptools