Stats: Deprecating old Stats experience (#37591)

* Stats: Update old Stats with a deprecation notice

* changelog

* Stats: Updating path source

* Update projects/plugins/jetpack/modules/stats.php

* Update projects/plugins/jetpack/modules/stats.php

* Update projects/plugins/jetpack/modules/stats.php

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Co-authored-by: Jasper Kang <jasper.kang@automattic.com>

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/9283641537

Upstream-Ref: Automattic/jetpack@0a6ac84