Preserving tmt state across reprovisioning

[cgwalters]

OK so the key issue here I think we want to keep /var/tmp/tmt across the reprovisioning?

tmt-bootc-install-switch/tests/bootc-install.sh

Line 62 in 6ced2bd

COPY tmt /var/tmp/tmt

This is OK for now, but I'd like to avoid a full local container build cycle for this by default. The feature we want here is something closer to bootc-dev/bootc#267

[henrywang]

There's a TMT bug to track this issue teemtee/tmt#3603.