Update runner of system-test to ubuntu-latest (#509)

.github/workflows/system-test.yaml

@@ -20,8 +20,7 @@ on:
 
 jobs:
   system-test:
-    # https://help.github.com/en/actions/automating-your-workflow-with-github-actions/software-installed-on-github-hosted-runners#ubuntu-1804-lts
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/setup-go@v3
         with:

system_test/Makefile

@@ -18,7 +18,7 @@ cluster: cert
 .PHONY: setup-chrome
 setup-chrome: cert
 	# add the dex server certificate to the trust store
-	if [ -d ~/.pki/nssdb ]; then certutil -A -d sql:$(HOME)/.pki/nssdb -n dex -i $(CERT_DIR)/ca.crt -t "TC,,"; fi
+	certutil -A -d sql:$(HOME)/.pki/nssdb -n dex -i $(CERT_DIR)/ca.crt -t "TC,,"
 
 .PHONY: cert
 cert: