Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: BlaiseD

src/AutoMapper.Extensions.ExpressionMapping/Properties/Resources.resx

@@ -148,7 +148,7 @@
     <comment>0=argumentType</comment>
   </data>
 	<data name="invalidTypeMappingsFormat" xml:space="preserve">
-    <value>Invalis type mappings. Source Type: {0}, Destination Type: {1}.</value>
+    <value>Invalid type mappings. Source Type: {0}, Destination Type: {1}.</value>
     <comment>0=sourceType; 1=destinationTyp;</comment>
   </data>
 </root>