Update release steps (#836)

Author: trask

.github/config/markdown-link-check-config.json

@@ -1,8 +1,11 @@
 {
-  "retryOn429" : true,
-  "ignorePatterns" : [
+  "retryOn429": true,
+  "ignorePatterns": [
     {
-      "pattern" : "^https://github\\.com/open-telemetry/opentelemetry-java-contrib/network/updates$"
+      "pattern": "^https://github\\.com/open-telemetry/opentelemetry-java-contrib/network/updates$"
+    },
+    {
+      "pattern": "^https://github.com/open-telemetry/opentelemetry-java-contrib/pulls/app%2Fdependabot$"
     }
   ]
 }

RELEASING.md

@@ -19,7 +19,9 @@ the second Monday of the month (roughly a couple of days after the monthly minor
 ## Preparing a new major or minor release
 
 * Check that [dependabot has run](https://github.com/open-telemetry/opentelemetry-java-contrib/network/updates)
-  sometime in the past day.
+  sometime in the past day and that all
+  [dependabot PRs](https://github.com/open-telemetry/opentelemetry-java-contrib/pulls/app%2Fdependabot)
+  have been merged.
   * Check that the OpenTelemetry SDK and Instrumentation versions have been updated to the latest release.
 * Close the [release milestone](https://github.com/open-telemetry/opentelemetry-java-contrib/milestones)
   if there is one.