chore(deps): update sourcegraph prometheus / grafana docker images to v6.8.2313

Author: renovate[bot]

docker-compose/docker-compose.yaml

@@ -419,7 +419,7 @@ services:
   #
   prometheus:
     container_name: prometheus
-    image: 'index.docker.io/sourcegraph/prometheus:6.1.2889@sha256:75fa45933ecb03f7aca1d54ec5ebc05d11ff300494a2ca8fbaefa25c83f0326f'
+    image: 'index.docker.io/sourcegraph/prometheus:6.8.2313@sha256:1d776e6199560a8ee1ff69123c39da557b9e5e8f2387912ce147979c62650748'
     cpus: 4
     mem_limit: '8g'
     volumes:
@@ -446,7 +446,7 @@ services:
   # 'GF_SERVER_ROOT_URL='https://grafana.example.com'
   grafana:
     container_name: grafana
-    image: 'index.docker.io/sourcegraph/grafana:6.3.3@sha256:2f68b9b1542e7d75459d983b606d2fdd1c11a75610464e3d7a6ced4f3ac474bf'
+    image: 'index.docker.io/sourcegraph/grafana:6.8.2313@sha256:7075b9319e17fc65fd6048ac2b5e97988bcd2dc06111d5b0919bba3799bcdbae'
     cpus: 1
     mem_limit: '1g'
     volumes: