Revert version bump, move notes to Unreleased, focus tests.

- Do not bump version.rb in the PR.
- Move the release note under ## Unreleased.
- Trim the non-blocking fiber tests to a focused set.

Assisted-By: devx/5f4cfab6-1d74-4100-8755-82d7c62c70ab

Author: samuel-williams-shopify

lib/async/version.rb

@@ -5,5 +5,5 @@
 
 # @namespace
 module Async
-	VERSION = "2.42.0"
+	VERSION = "2.41.0"
 end

releases.md

@@ -1,6 +1,6 @@
 # Releases
 
-## v2.42.0
+## Unreleased
 
   - `Sync` and `Async` can now be invoked from a non-blocking fiber that has no scheduler (e.g. inside an `Enumerator` or a bare `Fiber.new`). Previously this raised `RuntimeError: Running scheduler on non-blocking fiber!`. The reactor is now run within `Fiber.blocking`, so the scheduler always runs on a blocking fiber.
 

test/kernel/sync.rb

@@ -46,18 +46,6 @@
 
 		with "a non-blocking fiber" do
 			it "can run the scheduler on a non-blocking fiber" do
-				executed = false
-				
-				Fiber.new do
-					Sync do |task|
-						executed = true
-					end
-				end.resume
-				
-				expect(executed).to be == true
-			end
-			
-			it "returns the result of the block" do
 				result = Fiber.new do
 					Sync {|task| value}
 				end.resume
@@ -94,29 +82,6 @@
 				end.to raise_exception(StandardError, message: be =~ /boom/)
 			end
 
-			it "runs on the calling fiber, preserving fiber storage" do
-				Fiber[:annotation] = "outer"
-				
-				result = Fiber.new do
-					Sync {|task| Fiber[:annotation]}
-				end.resume
-				
-				expect(result).to be == "outer"
-			end
-			
-			it "supports nested synchronous tasks" do
-				result = Fiber.new do
-					Sync do |outer|
-						Sync do |inner|
-							expect(inner).to be_equal(outer)
-							value
-						end
-					end
-				end.resume
-				
-				expect(result).to be == value
-			end
-			
 			it "can be used from within an Enumerator" do
 				# The value is yielded *after* `Sync` returns, so the yield happens on the enumerator fiber:
 				enumerator = Enumerator.new do |yielder|