fix: Dockerfile.e2e to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE39-OPENSSL-1089232
- https://snyk.io/vuln/SNYK-ALPINE39-OPENSSL-1089232
- https://snyk.io/vuln/SNYK-ALPINE39-OPENSSL-1089234
- https://snyk.io/vuln/SNYK-ALPINE39-OPENSSL-1089235
- https://snyk.io/vuln/SNYK-ALPINE39-OPENSSL-1089235

Dockerfile.e2e

@@ -49,7 +49,7 @@ RUN hack/make.sh build-integration-test-binary
 RUN mkdir -p /build/tests && find . -name test.main -exec cp --parents '{}' /build/tests \;
 
 ## Generate testing image
-FROM alpine:3.9 as runner
+FROM alpine:3.14.4 as runner
 
 ENV DOCKER_REMOTE_DAEMON=1
 ENV DOCKER_INTEGRATION_DAEMON_DEST=/