feat: update .NET version to 9.0.100 in build workflow and global.json

Author: dagweg

.github/workflows/build-and-deploy.yml

@@ -9,7 +9,7 @@ on:
 env:
   AZURE_WEBAPP_NAME: frontierfinds
   AZURE_WEBAPP_PACKAGE_PATH: "./Source/Ecommerce.Api/publish"
-  DOTNET_VERSION: "9.x"
+  DOTNET_VERSION: "9.0.100"
   SOLUTION_PATH: "FrontierFinds.sln"
   API_PROJECT_PATH: "./Source/Ecommerce.Api"
   PUBLISH_DIR: "./publish"

global.json

@@ -2,4 +2,4 @@
   "sdk": {
     "version": "9.0.100"
   }
-}
+}