Remove redundant subnav on cve pages and tutorials

[mtruj013]

Done

• Removed redundant subnav on CVE pages and tutorial guide (see issues for context)

QA

• Check out this feature branch
• Run the site using the command ./run serve or dotrun
• View the site locally in your web browser at: https://ubuntu-com-11983.demos.haus/security/cves
• Click on any CVE (eg: https://ubuntu-com-11983.demos.haus/security/CVE-2021-46837)
• See that only 1 subnav exists
• Go to https://ubuntu-com-11983.demos.haus/tutorials/guidelines#1-overview
• See that only 1 subnav exists
  • Be sure to test on mobile, tablet and desktop screen sizes

Issue / Card

Fixes https://github.com/canonical/ubuntu.com/issues/11982, https://github.com/canonical/ubuntu.com/issues/11985

[webteam-app]

Demo starting at https://ubuntu-com-11983.demos.haus

[codecov-commenter]

Codecov Report

Merging #11983 (7af1e25) into main (059cd41) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##             main   #11983   +/-   ##
=======================================
  Coverage   64.15%   64.15%           
=======================================
  Files         119      119           
  Lines        2636     2636           
  Branches      773      773           
=======================================
  Hits         1691     1691           
  Misses        903      903           
  Partials       42       42           

[carkod]

Can you also fix it for tutorials? https://ubuntu-com-11983.demos.haus/tutorials/manage-ua-client-fips-configurations-at-scale-with-landscape#1-overview

Issue: https://github.com/canonical/ubuntu.com/issues/11985

[mtruj013]

@carkod I was going by what was on the spreadsheet that Dave left. But it does sound weird that they would all link to "How to write a tutorial" now that you mention it.

@sowasred2012 is the correct subnav link for any given tutorial supposed to be the first section of said tutorial or are they all supposed to link to the same thing?

[sowasred2012]

@carkod in the conversations I had with Dave about the subnav, the idea was for it to be consistent within a particular bubble i.e. the items shouldn't change, and also that we should never use breadcrumbs. Additionally, titles of tutorials can be quite long, and the work we recently did on the subnav was meant to reduce the length and number of items in the subnav ready for when we roll out the new nav design. I agree that "How to write a tutorial" looks odd there though.