bump to v1.15.0 (#2965)

* bump to v1.15.0
* more linter hints
* update dependencies of kubectl-pg plugin

e2e/Dockerfile

@@ -15,7 +15,7 @@ RUN apt-get update \
            curl \
            vim \
     && pip3 install --no-cache-dir -r requirements.txt \
-    && curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.24.3/bin/linux/amd64/kubectl \
+    && curl -LO https://dl.k8s.io/release/v1.32.9/bin/linux/amd64/kubectl \
     && chmod +x ./kubectl \
     && mv ./kubectl /usr/local/bin/kubectl \
     && apt-get clean \