ci(NODE-7593): switch off macos-13 to macos-26-intel

[PavelSafronov]

Description

Summary of Changes

macos-13 support was dropped (https://github.blog/changelog/2025-09-19-github-actions-macos-13-runner-image-is-closing-down/), so to continue testing Intel Mac, we're switching over to macos-15-intel, the closest comparable non-large runner.

Notes for Reviewers

What is the motivation for this change?

Current runner is deprecated, all PRs get stuck.

Double check the following

• Lint is passing (npm run check:lint)
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[Copilot]

Pull request overview

Updates the GitHub Actions workflow matrices to stop using the deprecated macos-13 runner image and continue running CI on an Intel macOS runner.

Changes:

• Replace macos-13 with macos-15-intel in the test workflow OS matrix.
• Replace macos-13 with macos-15-intel in the build workflow OS matrix.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
.github/workflows/test.yml	Updates the host test matrix to run on macos-15-intel instead of macos-13.
.github/workflows/build.yml	Updates the host build/test matrix to run on macos-15-intel instead of macos-13.

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[tadjik1]

@PavelSafronov thanks for looking into this issue!
What is the reason we run on macos-15-intel (quite old), and not, for example macos-26-intel?

[PavelSafronov]

@PavelSafronov thanks for looking into this issue! What is the reason we run on macos-15-intel (quite old), and not, for example macos-26-intel?

Looked into this, and there isn't a good reason to not choose 26: 26 is going to be the last version to run on the supported hardware, so it's the OS that is the most representative of real remaining Intel users. Switching to 26.

[tadjik1]

Thank you @PavelSafronov! 🥇