Remove support for 3.6

[ocelotl]

Fixes #2360 and because I am always looking for the corresponding contrib repo PR, here it is.

6 months have passed since 3.6 reached its end of life. Our policy requires we remove support for 3.6.

[srikanthccv]

There was some custom time_ns logic just for the 3.6 right?

[ocelotl]

There was some custom time_ns logic just for the 3.6 right?

Yes! Excellent, thanks for the reminder, I have been wanting to remove that 😝

[srikanthccv]

I see some other references to version_info < 3, 7 https://github.com/open-telemetry/opentelemetry-python/search?q=version_info&type=. I think we should address them as well.

[ocelotl]

I see some other references to version_info < 3, 7 https://github.com/open-telemetry/opentelemetry-python/search?q=version_info&type=. I think we should address them as well.

Removed them 👍