Add Infradev triaging to CA reaction rotation

Why is this change being made?

Add Infradev triaging to CA reaction rotation to make sure we regularly check these issues.

The infradev process is a company wide initiative to better address issues related to availability and reliability of GitLab.com.

The catalyst for us adding this to our reaction rotation is the recent events that occured and required a rapid-action to be created and related discussion from Product in Product#2185 (closed). Even is Secure is very rarely (if not never) involved in such issues we must be cautious with these as they can have a big impact on our SAAS.

As infradev issues are not only bugs, they might not be caught in our bugs triage process, hence the need for this additional issues board to be checked.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the "Maintained by" section in on the page being edited.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files. (this requirement has been removed pending identification of a new DRI for the handbook)

sites/handbook/source/handbook/engineering/development/secure/composition-analysis/index.html.md

@@ -52,6 +52,7 @@ There is no formal designation process yet, volunteers are welcome and rotation
 1. Triage vulnerabilities reported on the projects we maintain and help resolving them depending on their priority. (See [Security vulnerabilities triaging process](#security-vulnerabilities-triaging-process))
 1. Triage and work with community contributors to help drive their MRs to completion. (See [Community contributions triaging process](#community-contributions-triaging-process))
 1. Triage bugs and resolve them when given `~priority::1`. (See [Bugs triaging process](#bugs-triaging-process))
+1. Triage infradev issues and resolve them when given `~priority::1`. (See [Infradev triaging process](#infradev-triaging-process))
 These items must be triaged continuously throughout the month which means they must be checked multiple times a week.
@@ -99,6 +100,13 @@ If immediate feedback is required, then add a comment to the vulnerability issue
 1. Leverage the [Bug scrub issues board](https://gitlab.com/groups/gitlab-org/-/boards/1077546?scope=all&utf8=%E2%9C%93&label_name[]=bug&label_name[]=devops%3A%3Asecure&label_name[]=group%3A%3Acomposition%20analysis).
 1. For each open issue that has no Priority label ("Open" column), shortly investigate the bug (< 1h) and comment with your findings. Ideally you'd suggest Priority and Severity levels to guide PM decision.
+### Infradev triaging process
+
+1. Leverage the [Infra/Dev issues board](https://gitlab.com/groups/gitlab-org/-/boards/1193197?scope=all&utf8=%E2%9C%93&label_name[]=infradev&label_name[]=section%3A%3Asec) for Sec section. We target the whole section on purpose to cover a larger area and stay aware of other group's issues that could also affect us.
+1. For each open issue that has no Priority label ("Open" column), shortly investigate the issue (< 1h) and comment with your findings. Make sure correct stage and group label are applied. 
+
+Please refer to our [infradev process](https://about.gitlab.com/handbook/engineering/workflow/#infradev) for more details.
+
 ### Tech-debt and tooling triaging process
 To help our Product Manager decide which tech-debt and tooling issues to include in the upcoming milestone, the engineering teams assign them a [priority label](https://about.gitlab.com/handbook/engineering/quality/issue-triage/#priority).