test_posix_pty_functions fails on Solaris: slave is not a terminal

[serhiy-storchaka]

Bug report

test_posix_pty_functions fails on Solaris/illumos:

OSError: [Errno 25] Inappropriate ioctl for device

The test opens a pty slave with os.open() and expects os.ttyname() to work, but on System V-derived systems the slave is not a terminal until the ptem and ldterm STREAMS modules are pushed onto it. Push them on sunos.

Linked PRs

• gh-154226: Fix test_posix_pty_functions on Solaris #154230
• [3.15] gh-154226: Fix test_posix_pty_functions on Solaris (GH-154230) #154241
• [3.14] gh-154226: Fix test_posix_pty_functions on Solaris (GH-154230) #154242
• [3.13] gh-154226: Fix test_posix_pty_functions on Solaris (GH-154230) #154243