[Bug]: Extra padding on first tab under pinned tabs on vertical tab bar

[kgorol]

Pre-Submission Checklist

• [X] I have checked the existing/closed issues to ensure this issue has not already been reported.
• [X] I am using the latest supported version of the browser.
• [X] I have tried disabling all browser extensions/add-ons to rule out interference from these.
• [X] I have tried clearing the browser cache and cookies.
• [ ] I have checked with a new profile and the issue still occurs.
• [X] I have provided detailed step-by-step instructions on how to reproduce the issue.
• [X] I have included relevant screenshots or console outputs.
• [X] I have checked that this problem is not occurring in the latest version of Firefox ESR.
• [X] This issue is specific to this browser and does not occur in other browsers.

Bug Summary

As you can see on the screenshot below, the first tab under pinned tabs (below Tuta) as some extra padding on the left.

Reproduction Steps

1. Enable vertical tabs

Expected Behavior

No extra padding

Actual Behavior

Extra padding visible on first not pinned tab

Screenshots

Browser Version

11.17.5

Operating System

Windows 11

Additional Context

No response