Bump github.com/pb33f/libopenapi from 0.18.6 to 0.18.7

Bumps [github.com/pb33f/libopenapi](https://github.com/pb33f/libopenapi) from 0.18.6 to 0.18.7.
- [Release notes](https://github.com/pb33f/libopenapi/releases)
- [Commits](pb33f/libopenapi@v0.18.6...v0.18.7)

---
updated-dependencies:
- dependency-name: github.com/pb33f/libopenapi
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

go.mod

@@ -3,7 +3,7 @@ module github.com/pb33f/libopenapi-validator
 go 1.23.0
 
 require (
-	github.com/pb33f/libopenapi v0.18.6
+	github.com/pb33f/libopenapi v0.18.7
 	github.com/santhosh-tekuri/jsonschema/v6 v6.0.1
 	github.com/stretchr/testify v1.9.0
 	github.com/vmware-labs/yaml-jsonpath v0.3.2

go.sum

@@ -56,8 +56,8 @@ github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1y
 github.com/onsi/gomega v1.17.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/onsi/gomega v1.19.0 h1:4ieX6qQjPP/BfC3mpsAtIGGlxTWPeA3Inl/7DtXw1tw=
 github.com/onsi/gomega v1.19.0/go.mod h1:LY+I3pBVzYsTBU1AnDwOSxaYi9WoWiqgwooUqq9yPro=
-github.com/pb33f/libopenapi v0.18.6 h1:adxzZUnOBOAuKxFAIrtb1Qt8GA4XnDWUAxEnqiSoTh0=
-github.com/pb33f/libopenapi v0.18.6/go.mod h1:qZRs2IHIcs9SjHPmQfSUCyeD3OY9JkLJQOuFxd0bYCY=
+github.com/pb33f/libopenapi v0.18.7 h1:gLD4gQ88zEqv7x13SDzk3AUdpHUp9gWrP1NDwrFTy+U=
+github.com/pb33f/libopenapi v0.18.7/go.mod h1:qZRs2IHIcs9SjHPmQfSUCyeD3OY9JkLJQOuFxd0bYCY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/santhosh-tekuri/jsonschema/v6 v6.0.1 h1:PKK9DyHxif4LZo+uQSgXNqs0jj5+xZwwfKHgph2lxBw=