test(regress): re-generate expected/interval.out using default IntervalStyle

[xiangjinwu]

I hereby agree to the terms of the RisingWave Labs, Inc. Contributor License Agreement.

What's changed and what's your intention?

Similar to #8386 which handles timestamp.out and timestamptz.out.

Unlike the 2 files above, styles are already explicitly set and independent to environment. But when the subject being tested is not related to textual output style, we still want the default style IntervalStyle=postgres.

horology.out may need similar treatment, but deferred until more familiar with test cases inside.

Checklist For Contributors

• All checks passed in ./risedev check (or alias, ./risedev c)

Documentation

• My PR DOES NOT contain user-facing changes.

[codecov]

Codecov Report

Merging #8433 (a83497a) into main (10ebee3) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #8433      +/-   ##
==========================================
- Coverage   71.64%   71.64%   -0.01%     
==========================================
  Files        1135     1135              
  Lines      185621   185621              
==========================================
- Hits       132997   132991       -6     
- Misses      52624    52630       +6     

Flag	Coverage Δ
rust	71.64% <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	64.43% <0.00%> (-1.04%)	⬇️
src/batch/src/task/task_execution.rs	51.25% <0.00%> (-0.50%)	⬇️
src/storage/src/hummock/compactor/mod.rs	80.19% <0.00%> (-0.39%)	⬇️
src/meta/src/hummock/manager/mod.rs	78.83% <0.00%> (-0.07%)	⬇️
...frontend/src/scheduler/hummock_snapshot_manager.rs	60.47% <0.00%> (+0.47%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more