Respect constraints on tempest venv consistently

In case of online mode, there is a procedure to recreate tempest venv.
For consistency of tempest venv during the entire stack.sh process,
add logic to consider the TEMPEST_VENV_UPPER_CONSTRAINTS option here.

Closes-bug: #1980483
Signed-off-by: June Yi <june.yi@samsung.com>
Change-Id: I0cea282152fd363af8671cab1b5f733ebe2bd4df
1 file changed