Move windows/amd64 to Tier 1 - Primary Support

[pjanotti]

Is your feature request related to a problem? Please describe.
windows/amd64 is the most popular Windows deployment of the collector in production, at this stage we should be able to move it to tier 1 support as defined at https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/platform-support.md#tier-1--primary-support.

Describe the solution you'd like

• CI Test runs on Windows for PRs and release cycle, see related issues:
  • Run Windows tests by default opentelemetry-collector-contrib#34385
  • Add MSI smoke tests opentelemetry-collector-releases#576

[djaglowski]

I am supportive of this in principle but concerned about the limited number of contributors we have supporting windows. My suggestion is that we first enable CI tests for windows on all PRs and use this to build confidence that we're ready to declare this tier 1 support. Maybe we can do this for a month to observe the impact and gauge our ability to respond, and then decide if we're ready to declare tier 1 support?