CI: remove attempts: 3 from IaaS builds

These rarely fail intermittently and multiple attempts slow down
feedback. At least as of 2025...

Author: aramprice

ci/pipelines/stemcells-windows.yml

@@ -1372,7 +1372,6 @@ jobs:
       pre: build
     tags: [*worker_tag]
   - task: create-aws-stemcell
-    attempts: 3
     timeout: 2h
     file: bosh-windows-stemcell-builder-ci/ci/tasks/create-aws-stemcell/task.yml
     image: bosh-windows-stemcell-builder-ci-image
@@ -1546,7 +1545,6 @@ jobs:
       - get: windows-bsdtar
       - get: windows-winsw
   - task: create-aws-govcloud-stemcell
-    attempts: 3
     timeout: 1h30m
     file: bosh-windows-stemcell-builder-ci/ci/tasks/create-aws-stemcell/task.yml
     image: bosh-windows-stemcell-builder-ci-image
@@ -1712,7 +1710,6 @@ jobs:
       pre: build
     tags: [*worker_tag]
   - task: create-azure-stemcell
-    attempts: 3
     file: bosh-windows-stemcell-builder-ci/ci/tasks/create-azure-stemcell/task.yml
     image: bosh-windows-stemcell-builder-ci-image
     params:
@@ -1908,7 +1905,6 @@ jobs:
       pre: build
     tags: [*worker_tag]
   - task: create-gcp-stemcell
-    attempts: 3
     file: bosh-windows-stemcell-builder-ci/ci/tasks/create-gcp-stemcell/task.yml
     image: bosh-windows-stemcell-builder-ci-image
     params: