Upgrade to opentelemetry 0.26

[ymgyt]

Motivation

Update opentelemetry depencencies to 0.26
https://github.com/open-telemetry/opentelemetry-rust/releases/tag/opentelemetry-0.26.0

Solution

• Upgrade opentelemetry deps to 0.26
• Adapt to the API changes of OpenTelemetry's Key
  • https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry/CHANGELOG.md#changelog
• Adapt to the removal of the AggregationSelector trait and DefaultAggregationSelector struct in opentelemetry-sdk.
  • https://github.com/open-telemetry/opentelemetry-rust/blob/main/opentelemetry-sdk/CHANGELOG.md#v0260

[djc]

Thanks!

[djc]

I think we should just wait for an upstream fix for this instead of working around it like this.

[ymgyt]

@djc
As suggested in the review and issue, after executing cargo update, the error was resolved, and the line added to Cargo.toml:

tonic = { version = "0.12.3", optional = true }

became unnecessary.

[djc]

That's not actually a fix, that's a workaround. Submitted a fix in open-telemetry/opentelemetry-rust#2168.

[ymgyt]

Thank you for submitting the fix PR. I will update this PR once opentelemetry-proto version 0.26.1 is published.