✅ Simplify two DeprecatedClientOptions tests

These tests weren't even using the correct port for the fake server, so
there is reason to start it up at all.

Also, we have issues with reliably shutting the server down after an
error, for both TruffleRuby and JRuby.

Author: nevans

test/net/imap/test_deprecated_client_options.rb

@@ -87,31 +87,15 @@ class InitializeTests < DeprecatedClientOptionsTest
     end
 
     test "combined options hash and keyword args raises ArgumentError" do
-      ex = nil
-      run_fake_server_in_thread(
-        ignore_io_error: true, implicit_tls: true
-      ) do |server|
-        imap = Net::IMAP.new("localhost", {port: 993}, ssl: true)
-      rescue => ex
-        nil
-      ensure
-        imap&.disconnect
+      assert_raise_with_message ArgumentError, /deprecated.*keyword arg/ do
+        Net::IMAP.new("localhost", {port: 993}, ssl: true)
       end
-      assert_equal ArgumentError, ex.class
     end
 
     test "combined options hash and ssl args raises ArgumentError" do
-      ex = nil
-      run_fake_server_in_thread(
-        ignore_io_error: true, implicit_tls: true
-      ) do |server|
-        imap = Net::IMAP.new("localhost", {port: 993}, true)
-      rescue => ex
-        nil
-      ensure
-        imap&.disconnect
+      assert_raise_with_message ArgumentError, /deprecated SSL.*options hash/ do
+        Net::IMAP.new("localhost", {port: 993}, true)
       end
-      assert_equal ArgumentError, ex.class
     end
 
   end