build(deps): bump openpolicyagent/opa (#119)

Bumps the examples-ext-authz group in /ext_authz with 1 update: openpolicyagent/opa.


Updates `openpolicyagent/opa` from 0.67.1-istio to 0.68.0-istio

---
updated-dependencies:
- dependency-name: openpolicyagent/opa
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: examples-ext-authz
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

ext_authz/Dockerfile-opa

@@ -1,3 +1,3 @@
-FROM openpolicyagent/opa:0.67.1-istio@sha256:23c4493ebc01940586addcaef94ef85bfbc12acd60f7a8ab484a1a7ba2e5c3dd
+FROM openpolicyagent/opa:0.68.0-istio@sha256:95af3422ff3d055942a1e048e66b61ec97ae6d00613156e2836d2caff5b7f5bd
 
 COPY --chmod=644 ./config/opa-service/policy.rego /etc/policy.rego