Remove "Update from v2.5 > Update to latest v3.3" from nav

[adriendupuis]

Question	Answer
JIRA Ticket	IBX-9609
Versions	master, 4.6, 3.3
Edition	All

• Duplicates "Update from v3.3 > Update to v3.3.latest"
• Already linked at the end of "Update from v2.5 > Update to v3.3"
• Surprising ToC current item highlight behavior (unfold "Update from v2.5")
  • Currently: https://doc.ibexa.co/en/latest/update_and_migration/from_3.3/update_from_3.3/ (if you clicked the first, you ended on te second one which have another label)
  • If mkdocs is upgraded: https://ez-systems-developer-documentation--2627.com.readthedocs.build/en/2627/update_and_migration/from_3.3/update_from_3.3/ (two labels are highlighted as current, both have the same label, the first one)

Checklist

• Text renders correctly
• Text has been checked with vale
• Description metadata is up to date
• Redirects cover removed/moved pages
• Code samples are working
• PHP code samples have been fixed with PHP CS fixer
• Added link to this PR in relevant JIRA ticket or code PR

[github-actions]

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[mnocon]

Thanks!