gh-138744: Upgrade Windows to 2025 in GitHub Actions

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Replace windows-2022 with windows-2025.

• Issue: test_dtrace fails on Windows Server 2025 #138744

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I modified a random file (Lib/test/test_dtrace.py) to trigger the Windows CIs. I will revert this TEST change once I will have the confirmation that the Windows CIs pass.

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This change leaves .azure-pipelines/ci.yml unchanged, it still contains:

- job: Windows_CI_Tests
  ...
  pool:
    vmImage: windows-2022

I propose updating .azure-pipelines/ci.yml in a separated change.

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See also #144679 : we might wait and upgrade directly to windows-2025-vs2026 image.

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All Windows CI jobs passed successfully. Examples:

JIT / aarch64-pc-windows-msvc/msvc (Debug) (pull_request)
JIT / aarch64-pc-windows-msvc/msvc (Release) (pull_request)
JIT / i686-pc-windows-msvc/msvc (Debug) (pull_request)
JIT / i686-pc-windows-msvc/msvc (Release) (pull_request)
Tests / Windows (free-threading) / Build and test (arm64) (pull_request)
Tests / Windows (free-threading) / Build and test (x64) (pull_request)
Tests / Windows / Build and test (arm64) (pull_request)
Tests / Windows / Build and test (Win32) (pull_request)
Tests / Windows / Build and test (x64) (pull_request)
Tests / Windows MSI / installer for arm64 (pull_request)
Tests / Windows MSI / installer for x64 (pull_request)
Tests / Windows MSI / installer for x86 (pull_request)

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The PR is now ready for review.

I got the confirmation that Windows CI jobs pass successfully with this change, so I reverted the TEST change to trigger these jobs.

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@chris-eibl @zooba: So are you ok with this change?

[chris-eibl]

Yeah, we can upgrade to windows-2025-vs2026 in a further PR.