chore(deps): bump dictdumper pin in conda/requirements.txt and benchmark requirements #2447

Follow-up from PR #2445's cross-review (round 2).

conda/requirements.txt and examples/benchmark/requirements-common.txt still pin dictdumper==0.8.4.post6, while pyproject.toml now requires >=0.8.5 (#2442/#2445).

create-release.yml's Setup Conda Distribution step installs straight from the committed conda/requirements.txt rather than waiting on the Conda Update cron's regeneration. A release cut before that cron runs would ship 0.8.4.post6 — the version with the double-escaping/key-escaping defects #2442 just fixed around.

The benchmark file is lower-stakes (installs pcapkit with --no-deps and never writes dumper output), but should still track the real floor.

Fix: bump both pins to dictdumper>=0.8.5 (or whatever exact pin style each file already uses).