chore(deps): update pre-commit hook google/go-jsonnet to v0.21.0 (#366)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.pre-commit-config.yaml

@@ -1,7 +1,7 @@
 exclude: "^.*/vendor/.*$"
 repos:
   - repo: https://github.com/google/go-jsonnet
-    rev: v0.20.0
+    rev: v0.21.0
     hooks:
       - id: jsonnet-format
   - repo: https://github.com/pre-commit/pre-commit-hooks