fix: sales time of the ticket is passed, don't show event

[maze-runnar]

… on the start page

Fixes fossasia/open-event-frontend#5110

Checklist

• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream development branch.
• The unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

• All the functions created/modified in this PR contain relevant docstrings.

[codecov]

Codecov Report

Merging #7439 (9ab35c6) into development (ef592f0) will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           development    #7439   +/-   ##
============================================
  Coverage        65.28%   65.28%           
============================================
  Files              265      265           
  Lines            13220    13220           
============================================
  Hits              8631     8631           
  Misses            4589     4589           

Impacted Files	Coverage Δ
app/api/events.py	38.91% <ø> (ø)

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