support: accept resource attribute values not limited to string type in OTEL

### Is your proposal related to a problem?

In OpenTelemetry integration, Hasura currently only supports string-valued attributes for [Resource attributes](https://hasura.io/docs/latest/observability/opentelemetry/#attributes)

### Describe the solution you'd like

Ability to define values for Resource attributes, which are not only limited to string. For example, if I want to set version number which is typically in float type which would be passed as value from env var.

No file, test, or entry point is named. Start by locating Hasura's OpenTelemetry resource-attribute configuration and its existing tests; confirm how environment-variable values are parsed. Done means resource attributes accept numeric values such as a float as well as strings, with coverage for the new behavior.

Written by the indexing model from the issue text.