Enable Searching for Pwsh in the "Program Files (Arm)" directory on Windows Arm64

[tsmarvin]

PR Summary

• Begin searching for Pwsh in the "Program Files (Arm)" directory on windows arm64.
  • Note this will only look for the "Program Files (Arm)" directory if the default "Program Files" directory does not contain a PowerShell install.
• Add tests case documenting expected load order.
• Update test cases to refer to v7 instead of v6.
  • I realize that this doesn't actually matter as its just looking for the first integer it finds, but since PS6 has been out of support for several years I thought it was time to update.

PR Checklist

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• PR has a meaningful title
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[Copilot]

Pull Request Overview

This PR enhances the PowerShell executable search logic on Windows Arm64 by including the "Program Files (Arm)" directory. Key changes include:

• Adding an isArm64 flag in platform details.
• Iterating over multiple possible Program Files paths (including "Program Files (Arm)").
• Updating test cases to expect version 7 of PowerShell instead of version 6.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
test/core/platform.test.ts	Updated test cases to include "Program Files (Arm)" and version updates.
src/platform.ts	Added isArm64 property and modified the logic to try multiple Program Files paths.

Comments suppressed due to low confidence (1)

src/platform.ts:715

• Update the method's documentation to reflect the new return type, noting that it returns an array of possible ProgramFiles paths instead of a single string.

    }: { useAlternateBitness?: boolean } = {}): (string | undefined)[] {

[Copilot]

Consider adding a comment explaining the iteration over multiple ProgramFiles paths to clarify the search order and rationale.

Suggested change

	> {
	> {
	// Iterate over possible `ProgramFiles` paths to locate PowerShell installations.
	// This accounts for different system configurations, such as 32-bit and 64-bit installations,
	// and ensures compatibility with alternate bitness settings if specified.

[tsmarvin]

@microsoft-github-policy-service agree

[JustinGrote]

Thanks! Do we have a way to meaningfully test this? Do we need to spin up/add ARM to the testing matrix?

[tsmarvin]

Honestly I wasn't sure what the options were there.

I would certainly recommend spinning up an arm CI pipeline if its possible as the related PSES changed I linked doesn't seem to impact my x64 builds but I'm really not sure why tbh.

I did add the unit tests to describe the expected order as interim support.

[tsmarvin]

Bah, I thought I re-ran the formatter before committing. Sorry about that, I'll get that fixed later tonight