crypto/tls: omit PSK in ECH outer client hello [1.25 backport]

[gopherbot]

@rbqvq requested issue #79282 to be considered for backport to the next 1.25 minor release.

@gopherbot please open backport issues

[gopherbot]

Change https://go.dev/cl/794920 mentions this issue: [release-branch.go1.25] crypto/tls: omit PSK in ECH outer client hello

[gopherbot]

Closed by merging CL 794920 (commit fc9f821) to release-branch.go1.25.