Migrate AtlassianPS.Configuration tests to Pester 6.2

[lipkau]

Summary

• Update AtlassianPS.Standards and all immutable shared workflow pins to v0.4.0.
• Pin lint and unit-test execution to Pester 6.2.0.
• Allow Pester 6.2.0 through the 6.x line in all source test headers and the test template.
• Record the new test toolchain in the changelog.

Compatibility and scope

Issue #12 identified no Configuration-specific Pester compatibility changes. The full generated Release suite passes without assertion, discovery, mock, or runtime-code changes. Windows PowerShell 5.1 remains supported.

This PR does not change module runtime behavior, persisted configuration data, workflow semantics, shuffle settings, parallel execution, or other optional Pester 6 features.

Validation

• Pester 5.9.1 baseline, Invoke-Build -Task Build, Test: 964 total, 945 passed, 0 failed, 19 skipped.
• Pester 6.2.0 with Standards 0.4.0, Invoke-Build -Task Lint, Build, Test: lint 6 passed; full Release suite 964 total, 945 passed, 0 failed, 19 skipped, 0 not run, 0 failed blocks, 0 failed containers.
• actionlint 1.7.12 passed against all workflows.
• git diff --check passed.
• Final requirement and scope audit found no issues. The secondary reviewer was unavailable because the collaborator quota was exhausted.

Test-count comparison

The full suite remains at 964 tests: 945 passed and 19 skipped. No tests were added, removed, renamed, newly skipped, or undiscovered compared with the Pester 5 baseline.

Release intent

Build and test infrastructure only. No package release.

Related

• Migrate AtlassianPS test suites to Pester 6.2 AtlassianPS#12