fix: update PR labeler to include SDK

Updates the PR labeler to correctly label the SDK. I noticed that the
SDK was not being correctly labeled and realized that I had to add it to
this file.

.github/labeler.yml

@@ -30,5 +30,8 @@ M-core-utils:
 M-dtl:
   - any: ['packages/data-transport-layer/**/*']
 
+M-sdk:
+  - any: ['packages/sdk/**/*']
+
 M-ops:
   - any: ['ops/**/*']