build(deps): bump github.com/go-openapi/spec from 0.20.7 to 0.20.8

Bumps [github.com/go-openapi/spec](https://github.com/go-openapi/spec) from 0.20.7 to 0.20.8.
- [Release notes](https://github.com/go-openapi/spec/releases)
- [Commits](go-openapi/spec@v0.20.7...v0.20.8)

---
updated-dependencies:
- dependency-name: github.com/go-openapi/spec
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -37,7 +37,7 @@ require (
 	github.com/go-openapi/errors v0.20.3
 	github.com/go-openapi/loads v0.21.2
 	github.com/go-openapi/runtime v0.25.0
-	github.com/go-openapi/spec v0.20.7
+	github.com/go-openapi/spec v0.20.8
 	github.com/go-openapi/strfmt v0.21.3
 	github.com/go-openapi/swag v0.22.3
 	github.com/go-openapi/validate v0.22.0

vendor/modules.txt

@@ -426,7 +426,7 @@ github.com/go-openapi/runtime/middleware/header
 github.com/go-openapi/runtime/middleware/untyped
 github.com/go-openapi/runtime/security
 github.com/go-openapi/runtime/yamlpc
-# github.com/go-openapi/spec v0.20.7
+# github.com/go-openapi/spec v0.20.8
 ## explicit; go 1.13
 github.com/go-openapi/spec
 # github.com/go-openapi/strfmt v0.21.3