fix(smart-contracts): remove limitation on max number of keys

[julien51]

Description

We should not prevent a lock manager from setting a value lower than supply.
In practice we already allow for that state (number of keys > maxKeysForSale) because we let lock manager airdrop keys to users even when we are above the limit!

Checklist:

• 1 PR, 1 purpose: my Pull Request applies to a single purpose
• I have commented my code, particularly in hard-to-understand areas
• I have updated the docs to reflect my changes if applicable
• I have added tests (and stories for frontend components) that prove my fix is effective or that my feature works
• I have performed a self-review of my own code
• If my code involves visual changes, I am adding applicable screenshots to this thread

Release Note Draft Snippet