Update secessentialshandson5.md to remove repeated word

Why is this change being made?

• Update secessentialshandson5.md to remove repeated word

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• Provided a concise title for this Merge Request (MR)

• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what

  • Copy/paste the Slack conversation to document it for later, or upload screenshots. Verify that no confidential data is added, and the content is SAFE

• Assign reviewers for this MR to the correct Directly Responsible Individual/s (DRI)

• For transparency, share this MR with the audience that will be impacted.

  • Team: For changes that affect your direct team, share in your group Slack channel
  • Department: If the update affects your department, share the MR in your department Slack channel
  • Company: If the update affects all (or the majority of) GitLab team members, post an update in #whats-happening-at-gitlab linking to this MR
    • For high-priority company-wide announcements work with the internal communications team to post the update in #company-fyi and align on a plan to circulate in additional channels like the "While You Were Iterating" Newsletter

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