Update multi column null constraint

What does this MR do and why?

This MR removes the software_license or custom_software_license constraint on software_license_policies. Without this constraint, it is possible to link software_license_policies to both software_license and custom_software_license.

This change is required to make the migration to the custom_software_license reversible.

Migration up

main: == 20241204180053 RemoveSoftwareLicenseExistenceConstraintToSoftwareLicensePolicies: migrating 
main: -- transaction_open?(nil)
main:    -> 0.0000s
main: -- transaction_open?(nil)
main:    -> 0.0000s
main: -- execute("            ALTER TABLE software_license_policies\n            DROP CONSTRAINT IF EXISTS check_9ba23ae4c3\n")
main:    -> 0.0013s

Migration down

main: == 20241204180053 RemoveSoftwareLicenseExistenceConstraintToSoftwareLicensePolicies: reverting 
main: -- transaction_open?(nil)
main:    -> 0.0000s
main: -- transaction_open?(nil)
main:    -> 0.0000s
main: -- execute("ALTER TABLE software_license_policies\nADD CONSTRAINT check_9ba23ae4c3\nCHECK ( num_nonnulls(custom_software_license_id, software_license_id) = 1 )\nNOT VALID;\n")
main:    -> 0.0033s
main: -- execute("SET statement_timeout TO 0")
main:    -> 0.0004s
main: -- execute("ALTER TABLE software_license_policies VALIDATE CONSTRAINT check_9ba23ae4c3;")
main:    -> 0.0060s
main: -- execute("RESET statement_timeout")
main:    -> 0.0005s
main: == 20241204180053 RemoveSoftwareLicenseExistenceConstraintToSoftwareLicensePolicies: reverted (0.0548s) 

References

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• Related to #478520 (closed)

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