Update OpenTelemetry libraries to latest versions

[martincostello]

👋 from the OpenTelemetry .NET folks.

Via dotnet/core#10399 I discovered that you're planning to depend on the OTel SDK in the dotnet CLI. That's cool 😎.

Looking at the code in main, you currently depend on 1.12.0:

sdk/eng/Versions.props

Line 63 in 2bbd50d

<OpenTelemetryVersion>1.12.0</OpenTelemetryVersion>

We recently (last week) published a number of GitHub Security Advisories that affect versions < 1.15.x (opentelemetry-dotnet advisories, opentelemetry-dotnet-contrib advisories).

I would recommend:

1. Upgrading to the latest versions.
2. Separating the versions here because they are not guaranteed to have matching versions (this is true for the latest versions patched right now, which are 1.15.3, 1.15.3, 1.15.1 and 1.15.1 respectively)

I'm sure you're probably already aware of this the NuGet Audit feature and you need to vendor the code at some point for source build anyway, but I thought I would bring this to your attention.

[baronfel]

Thanks! Yeah we're aware (but very much appreciate you reaching out!) - there's some delay because we need to bump the source-build external pins before that can flow. I'll log an issue there and link it (dotnet/source-build-assets#1649) here so we can at least get that ball rolling.