Support prom-client 15

[steven-sheehy]

Dependabot is attempting to update our dependency on prom-client from 14 to 15 but it fails due to swagger-stats explicitly only supporting up to 14. Is it possible to add support for prom-client 15? Note that 15 drop support for Node.js versions 10, 12, 14, 17 and 19 per its changelog, so that might be a blocker.

npm ERR! Conflicting peer dependency: prom-client@14.2.0
npm ERR! node_modules/prom-client
npm ERR!   peer prom-client@">= 10 <= 14" from swagger-stats@0.99.7
npm ERR!   node_modules/swagger-stats
npm ERR!     bundled swagger-stats@"^0.99.7" from the root project