fix: use catbox policy.get for proper concurrency handling

[kalinkrustev]

Catbox clients are not supposed to be used directly. Instead we must use the Catbox.Policy class, which implements a proper handling of the get() - specifically this:

Multiple concurrent requests are queued and processed once

Usage of set() is not required, instead we pass a generateFunc to the Policy
See the docs of the Policy.get() here https://hapi.dev/module/catbox/api/?v=12.1.1#api-1

[sonarqubecloud]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.6% Duplication on New Code

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