build(deps): bump github.com/open-policy-agent/opa from 1.5.1 to 1.6.0

Bumps [github.com/open-policy-agent/opa](https://github.com/open-policy-agent/opa) from 1.5.1 to 1.6.0.
- [Release notes](https://github.com/open-policy-agent/opa/releases)
- [Changelog](https://github.com/open-policy-agent/opa/blob/main/CHANGELOG.md)
- [Commits](https://github.com/open-policy-agent/opa/compare/v1.5.1...v1.6.0)

---
updated-dependencies:
- dependency-name: github.com/open-policy-agent/opa
  dependency-version: 1.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

vendor/github.com/vektah/gqlparser/v2/gqlerror/error.go

@@ -164,6 +164,15 @@ func ErrorPathf(path ast.Path, message string, args ...interface{}) *Error {
 }
 
 func ErrorPosf(pos *ast.Position, message string, args ...interface{}) *Error {
+	if pos == nil {
+		return ErrorLocf(
+			"",
+			-1,
+			-1,
+			message,
+			args...,
+		)
+	}
 	return ErrorLocf(
 		pos.Src.Name,
 		pos.Line,

vendor/github.com/vektah/gqlparser/v2/parser/parser.go

@@ -1,7 +1,6 @@
 package parser
 
 import (
-	"fmt"
 	"strconv"
 
 	"github.com/vektah/gqlparser/v2/ast"
@@ -106,7 +105,7 @@ func (p *parser) next() lexer.Token {
 	// Increment the token count before reading the next token
 	p.tokenCount++
 	if p.maxTokenLimit != 0 && p.tokenCount > p.maxTokenLimit {
-		p.err = fmt.Errorf("exceeded token limit of %d", p.maxTokenLimit)
+		p.err = gqlerror.Errorf("exceeded token limit of %d", p.maxTokenLimit)
 		return p.prev
 	}
 	if p.peeked {