Bump envoy-base-utils from 0.4.21 to 0.4.23 in /tools/base

Bumps [envoy-base-utils](https://github.com/envoyproxy/toolshed) from 0.4.21 to 0.4.23.
- [Release notes](https://github.com/envoyproxy/toolshed/releases)
- [Commits](https://github.com/envoyproxy/toolshed/commits)

---
updated-dependencies:
- dependency-name: envoy-base-utils
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

tools/base/requirements.txt

@@ -334,9 +334,9 @@ envoy-base-runner==0.1.1 \
     #   -r requirements.in
     #   envoy-base-checker
     #   envoy-docs-sphinx-runner
-envoy-base-utils==0.4.21 \
-    --hash=sha256:37e79232261a2b741ce75a7f25344ca3254a0fbbd40954a4e5367d0673559ad7 \
-    --hash=sha256:b41a143edac4bf8a09d6f2f222740e82f78fed000e736e5f3029c2d807c02445
+envoy-base-utils==0.4.23 \
+    --hash=sha256:3812ec04ee194bfbc6da2ba94efb0a210fd4d2f5714a55f0131e0af1166de74f \
+    --hash=sha256:67f2d36cbd5a5bb1743cf21b49bea4b6fe54000f0b8d9dedf40f0d85fc8e494b
     # via
     #   -r requirements.in
     #   envoy-dependency-pip-check