Update loki config, fix deprecated code

[mehr74]

boltdb-shipper is now deprecated, and loki container fails to come up. With the following error:

level=error ts=2024-10-25T11:36:13.764610843Z caller=main.go:70 msg="validating config" err="MULTIPLE CONFIG ERRORS FOUND, PLEASE READ CAREFULLY\nCONFIG ERROR: schema v13 is required to store Structured Metadata and use native OTLP ingestion, your schema version is v11. Set `allow_structured_metadata: false` in the `limits_config` section or set the command line argument `-validation.allow-structured-metadata=false` and restart Loki. Then proceed to update to schema v13 or newer before re-enabling this config, search for 'Storage Schema' in the docs for the schema update procedure\nCONFIG ERROR: `tsdb` index type is required to store Structured Metadata and use native OTLP ingestion, your index type is `boltdb-shipper` (defined in the `store` parameter of the schema_config). Set `allow_structured_metadata: false` in the `limits_config` section or set the command line argument `-validation.allow-structured-metadata=false` and restart Loki. Then proceed to update the schema to use index type `tsdb` before re-enabling this config, search for 'Storage Schema' in the docs for the schema update procedure"

The pull request should solve the issue with Loki connection.