fix(e2e): cleanup after extreme null test

[kwannoel]

As per title.

Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests
• All checks passed in ./risedev check (or alias, ./risedev c)

Refer to a related PR or issue link (optional)

[neverchanje]

My fault, lgtm

[codecov]

Codecov Report

Merging #3079 (5b8d2dd) into main (bcb9ffa) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3079      +/-   ##
==========================================
- Coverage   73.50%   73.50%   -0.01%     
==========================================
  Files         732      732              
  Lines       99526    99526              
==========================================
- Hits        73155    73153       -2     
- Misses      26371    26373       +2     

Flag	Coverage Δ
rust	73.50% <ø> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/meta/src/hummock/mock_hummock_meta_client.rs	43.82% <0.00%> (-1.13%)	⬇️
src/storage/src/hummock/local_version_manager.rs	84.12% <0.00%> (-0.16%)	⬇️

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