Remove fbossci account build-windows-ami (#7898)

This step is broken:
https://github.com/pytorch/test-infra/actions/runs/23565280903/job/68615184715#step:5:305
We are changing AMI publishing workflow. Hence no longer will be
building AMI on fbossci but using public AMI built by
``build-windows-ami`` step

Author: atalman

.github/workflows/build-windows-ami.yml

@@ -45,29 +45,3 @@ jobs:
           cd aws/ami/windows
           packer init .
           PACKER_LOG=1 packer build -var 'skip_create_ami=${{ inputs.skip_create_ami }}' .
-
-  build-windows-ami-pytorch-account:
-    runs-on: ubuntu-latest
-    environment: packer-build-env
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          repository: pytorch/test-infra
-          ref: ${{ inputs.branch }}
-
-      - name: Configure AWS Credentials (PyTorch Account)
-        uses: aws-actions/configure-aws-credentials@50ac8dd1e1b10d09dac7b8727528b91bed831ac0 # v3.0.2
-        with:
-          aws-region: us-east-1
-          role-to-assume: arn:aws:iam::308535385114:role/gha_workflow_build_packer_ami
-
-      - name: Setup Packer
-        uses: hashicorp/setup-packer@76e3039aa951aa4e6efe7e6ee06bc9ceb072142d # main
-        with:
-          version: ${{ env.PACKER_VERSION }}
-
-      - name: Packer Build
-        run: |
-          cd aws/ami/windows
-          packer init .
-          PACKER_LOG=1 packer build -var 'skip_create_ami=${{ inputs.skip_create_ami }}' .