Remove deserialize spec (Azure#51291)

Author: JoshLove-msft

eng/packages/http-client-csharp/eng/scripts/Generate.ps1

@@ -63,6 +63,7 @@ $failingSpecs = @(
     # Azure scenarios not yet buildable
     Join-Path 'http' 'client' 'namespace'
     Join-Path 'http' 'azure' 'client-generator-core' 'client-initialization'
+    Join-Path 'http' 'azure' 'client-generator-core' 'deserialize-empty-string-as-null' # long path issue and also not needed for Azure emitter
     Join-Path 'http' 'azure' 'core' 'scalar'
     Join-Path 'http' 'azure' 'core' 'traits'
     Join-Path 'http' 'azure' 'payload' 'pageable'

eng/packages/http-client-csharp/generator/Azure.Generator/src/Properties/launchSettings.json

@@ -45,11 +45,6 @@
       "commandName": "Executable",
       "executablePath": "dotnet"
     },
-    "http-azure-client-generator-core-deserialize-empty-string-as-null": {
-      "commandLineArgs": "$(SolutionDir)/../dist/generator/Microsoft.TypeSpec.Generator.dll $(SolutionDir)/TestProjects/Spector/http/azure/client-generator-core/deserialize-empty-string-as-null -g AzureStubGenerator",
-      "commandName": "Executable",
-      "executablePath": "dotnet"
-    },
     "http-azure-client-generator-core-flatten-property": {
       "commandLineArgs": "$(SolutionDir)/../dist/generator/Microsoft.TypeSpec.Generator.dll $(SolutionDir)/TestProjects/Spector/http/azure/client-generator-core/flatten-property -g AzureStubGenerator",
       "commandName": "Executable",