Add schema_url to TracerProvider.get_tracer

[NathanielRN]

Follow up to #1862

The spec in 1.4.0 added an optional parameter schema_url to the TracerProvider.get_tracer method which we still need to implement:

opentelemetry-python/opentelemetry-api/src/opentelemetry/trace/__init__.py

Lines 184 to 190 in 67bbad4

	class TracerProvider(ABC):
	@abstractmethod
	def get_tracer(
	self,
	instrumenting_module_name: str,
	instrumenting_library_version: str = "",
	) -> "Tracer":

We would need to update the API package + the SDK package.

[JamesJHPark]

@codeboten - please assign me this issue

[srikanthccv]

Fixed in #2154