Cannot connect to valkey/redis through rediss://

Preconditions and environment

• Magento version 2.4.8
• Anything else that would help a developer reproduce the bug: Have a valkey instance that doesnt respond to TLS.

I've also created an issue in the redis library magento2 uses.

Steps to reproduce

Have a valkey instance running, only accepting connections through redis:// similarly to the digital ocean docs

Expected result

Successfully connects

Actual result

Try to connect. Logs will show Connection to Redis standalone tcp://rediss://private-cache.com

Additional information

Seems setting the session in env.php will cause this, while the other caches will silently fail, and fall back to filesystem cache.

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.