fix: Make WIF pool datasource conditional on reuse

[nkraemer-sysdig]

Make the WIF pool datasource conditional, based on var.reuse_workload_identity_pool.

For fresh installs, attempting to load this datasource fails, and it is always loaded.

[wideawakening]

the applied change would also be required on other datasources such as the topic
for a quicker and more effective fix i recommend pinning versions so stick within majors whenever we find something with breaking change on our code.