Remote-SSH connection fails when the generated VS Code host alias is long (“ControlPath too long”)

[lennmail]

The VS Code host alias generated for Coder workspaces can be very long. This pushes OpenSSH’s ControlPath over its 108-byte limit, and the connection fails with:

ControlPath too long ('/home/<user>/.ssh/master-<user>@<generated-alias>:22' >= 108 bytes) ssh child died, shutting down