Remove the deprecated Inject and Extract from `otelgrpc`

[MrAlias]

Blocked by #7687
Blocked by https://github.com/open-telemetry/opentelemetry-go-contrib/milestone/32

opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc/metadata_supplier.go

Lines 42 to 51 in 73fe37d

	// Inject injects correlation context and span context into the gRPC
	// metadata object. This function is meant to be used on outgoing
	// requests.
	// Deprecated: Unnecessary public func.
	func Inject(ctx context.Context, md *metadata.MD, opts ...Option) {
	c := newConfig(opts)
	c.Propagators.Inject(ctx, &metadataSupplier{
	metadata: *md,
	})
	}

opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc/metadata_supplier.go

Lines 64 to 75 in 73fe37d

	// Extract returns the correlation context and span context that
	// another service encoded in the gRPC metadata object with Inject.
	// This function is meant to be used on incoming requests.
	// Deprecated: Unnecessary public func.
	func Extract(ctx context.Context, md *metadata.MD, opts ...Option) (baggage.Baggage, trace.SpanContext) {
	c := newConfig(opts)
	ctx = c.Propagators.Extract(ctx, &metadataSupplier{
	metadata: *md,
	})
	return baggage.FromContext(ctx), trace.SpanContextFromContext(ctx)
	}

[nithinputhenveettil]

@MrAlias : Could you please assign this to me? I’d like to take it up and work on this.

[pellared]

@nithinputhenveettil, I want to notice that this is not targeting the upcoming release (where we deprecate the function), but the release following it. Therefore, a PR won't be merged before v1.38.0 is released.

[nithinputhenveettil]

@pellared : Got it. If it's alright, please feel free to assign it to me. I can raise a draft PR in the meantime, if that works for you.

[MrAlias]

Hmm, it looks like these deprecations were not properly formatted. They were deprecated over 3 years ago, but the deprecation is missing a blank like above it. They are not deprecated based on tooling or docs:

• https://pkg.go.dev/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc#Inject
• https://pkg.go.dev/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc#Extract

We need to first fix the deprecation.