[tests-only][full-ci] test: fix flaky grouped email notification

[anon-pradip]

Description

Fixes two unrelated causes of failure in the grouped email notification tests (cliCommands suite).

1. Timezone (local only). The test built the expected expiry in UTC, but oCIS prints it in the server's timezone, so on a non-UTC host they never matched:

oCIS emailed "... expired at 2026-09-03 05:45:00" <- server timezone (+05:45)
test expected "... expired at 2026-09-03 00:00:00" <- UTC

The email body has no offset, so it can't be converted. Instead the expected value is rendered in the timezone from the mail's own Date header, which comes from the same message being asserted.

• EmailContext.php - reads the mail's Date timezone and resolves %expiry_date_in_mail% after the mail is fetched.
• FeatureContext.php - expiry is a DateTimeImmutable in UTC; %expiry_date_in_mail% is removed from the global substitutions.
• SpacesContext.php - expiration dates from the Graph API are converted to UTC before taking the date, instead of slicing the server's local date.
• bootstrap.php - pins PHP to UTC so every workspace behaves the same regardless of its php.ini.

2. Flakiness (CI). oCIS only evaluates expirations when a resource is accessed (#10966, #11690). The scenario never read the space after expiring the membership, so SpaceMembershipExpired was only published if an unrelated async handler happened to. emailNotification.feature now asserts the user "Brian" should not have a space called "New-Space", which forces the check and verifies the membership ended.

Related Issue

• Part of: CI tests have become increasingly flaky #12764

Motivation and Context

emailNotification.feature was flaky in CI and always failed locally on non-UTC machines.

How Has This Been Tested?

• Locally and CI.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:

[kw-security]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues
✅	Code Security	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[PrajwolAmatya]

LGTM