Bump pipeline generator to 1.1.0-dev.20260909.1 (#10275)

Co-authored-by: Ray Chen <raychen@microsoft.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: 3 people

eng/common/pipelines/templates/steps/install-pipeline-generation.yml

@@ -9,7 +9,7 @@ steps:
   - script: >
       dotnet tool install
       Azure.Sdk.Tools.PipelineGenerator
-      --version 1.1.0-dev.20260901.1
+      --version 1.1.0-dev.20260909.1
       --add-source https://pkgs.dev.azure.com/azure-sdk/public/_packaging/azure-sdk-for-net/nuget/v3/index.json
       --tool-path ${{parameters.ToolPath}}
     workingDirectory: $(Pipeline.Workspace)/pipeline-generator