build(deps): bump github.com/casbin/casbin/v2 in /casbin

Bumps [github.com/casbin/casbin/v2](https://github.com/casbin/casbin) from 2.52.2 to 2.54.0.
- [Release notes](https://github.com/casbin/casbin/releases)
- [Changelog](https://github.com/casbin/casbin/blob/master/.releaserc.json)
- [Commits](casbin/casbin@v2.52.2...v2.54.0)

---
updated-dependencies:
- dependency-name: github.com/casbin/casbin/v2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

casbin/go.mod

@@ -3,6 +3,6 @@ module github.com/gofiber/contrib/casbin
 go 1.16
 
 require (
-	github.com/casbin/casbin/v2 v2.52.2
+	github.com/casbin/casbin/v2 v2.54.0
 	github.com/gofiber/fiber/v2 v2.37.1
 )

casbin/go.sum

@@ -2,8 +2,8 @@ github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible h1
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
 github.com/andybalholm/brotli v1.0.4 h1:V7DdXeJtZscaqfNuAdSRuRFzuiKlHSC/Zh3zl9qY3JY=
 github.com/andybalholm/brotli v1.0.4/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
-github.com/casbin/casbin/v2 v2.52.2 h1:abZxXXlFu0Yl9IR8h7awjtr+iQ4k4Hmzvgn7bdLenNk=
-github.com/casbin/casbin/v2 v2.52.2/go.mod h1:vByNa/Fchek0KZUgG5wEsl7iFsiviAYKRtgrQfcJqHg=
+github.com/casbin/casbin/v2 v2.54.0 h1:NFQ3Xkw6rfbD/rwEHMVRHVP5gUxhNQKdcZCb53pwSrA=
+github.com/casbin/casbin/v2 v2.54.0/go.mod h1:vByNa/Fchek0KZUgG5wEsl7iFsiviAYKRtgrQfcJqHg=
 github.com/gofiber/fiber/v2 v2.37.1 h1:QK2032gjv0ulegpv/qlTEBoXQD3eFFzCHXcNN12UZCs=
 github.com/gofiber/fiber/v2 v2.37.1/go.mod h1:j3UslgQeJQP3mNhBxHnLLE8TPqA1Fd/lrl4gD25rRUY=
 github.com/golang/mock v1.4.4 h1:l75CXGRSwbaYNpl/Z2X1XIIAMSCquvXgpVZDhwEIJsc=