Improve labeler rules for kernel label (#724)

### Motivation and Context
#710 tried to enable the `kernel` tag but accidentally applied to too
many changes.

### Description
The best way to resolve this was specify directories under `dotnet` to
be considered for `kernel`.
 
 lemillermicrosoft#7
 lemillermicrosoft#8
 lemillermicrosoft#10
lemillermicrosoft#9 This one was
missed before.

.github/labeler.yml

@@ -1,34 +1,26 @@
-# Add 'kernel' label to any change within the 'dotnet/src' that's not 'SemanticKernel' or 'SemanticKernel.Abstractions' directory
+# Add 'kernel' label to any change within Connectors, Extensions, Skills, and tests directories
 kernel:
-  - any: ["dotnet/src/**/*", "dotnet/src/*"]
-  - all:
-      [
-        "!dotnet/src/SemanticKernel/*",
-        "!dotnet/src/SemanticKernel/**/*",
-        "!dotnet/src/SemanticKernel.Abstractions/*",
-        "!dotnet/src/SemanticKernel.Abstractions/**/*",
-      ]
+  - "dotnet/src/Connectors/**/*"
+  - "dotnet/src/Extensions/**/*"
+  - "dotnet/src/Skills/**/*"
+  - "dotnet/src/IntegrationTests/**/*"
+  - "dotnet/src/SemanticKernel.UnitTests/**/*"
 
-# Add 'kernel.core' label to any change within the 'SemanticKernel' or 'SemanticKernel.Abstractions' directory
+# Add 'kernel.core' label to any change within the 'SemanticKernel', 'SemanticKernel.Abstractions', or 'SemanticKernel.MetaPackage' directories
 kernel.core:
-  - dotnet/src/SemanticKernel/*
   - dotnet/src/SemanticKernel/**/*
-  - dotnet/src/SemanticKernel.Abstractions/*
   - dotnet/src/SemanticKernel.Abstractions/**/*
+  - dotnet/src/SemanticKernel.MetaPackage/**/*
 
 # Add 'python' label to any change within the 'python' directory
 python:
-  - python/*
   - python/**/*
 
 # Add 'samples' label to any change within the 'samples' directory
 samples:
-  - samples/*
   - samples/**/*
 
 # Add '.NET' label to any change within samples or kernel 'dotnet' directories.
 .NET:
-  - dotnet/src/*
   - dotnet/src/**/*
   - samples/**/dotnet/**/*
-  - samples/**/dotnet/*