refactor: reuse registry-mock in benchmark

[github-actions[bot]]

Micro-Benchmark Results

Linux

group                          main                                   pr
-----                          ----                                   --
tarball/download_dependency    1.00      6.6±0.27ms   654.7 KB/sec    1.01      6.7±0.18ms   648.0 KB/sec

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (f802fdf) 87.01% compared to head (90a8659) 87.01%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #201 +/- ## ======================================= Coverage 87.01% 87.01% ======================================= Files 56 56 Lines 2827 2827 ======================================= Hits 2460 2460 Misses 367 367 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[github-actions[bot]]

Integrated-Benchmark Report (Linux)

Scenario: Frozen Lockfile

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
pacquet@HEAD	147.3 ± 12.4	127.6	164.8	1.08 ± 0.12
pacquet@main	136.3 ± 10.8	121.7	162.7	1.00

BENCHMARK_REPORT.json

```json { "results": [ { "command": "pacquet@HEAD", "mean": 0.14731798808615387, "stddev": 0.012400072867997354, "median": 0.14428430624000002, "user": 0.059398547692307686, "system": 0.21270206, "min": 0.12762173724, "max": 0.16484519024000002, "times": [ 0.16484519024000002, 0.15330262124000002, 0.16277947424000003, 0.13891348424000002, 0.14428430624000002, 0.13591986824000002, 0.15739642224000003, 0.12762173724, 0.13905768624, 0.15819446024000003, 0.14159386524, 0.13259932924, 0.15862540024000002 ], "exit_codes": [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ] }, { "command": "pacquet@main", "mean": 0.13626936124000003, "stddev": 0.010774356275598567, "median": 0.13417019524, "user": 0.06078617333333332, "system": 0.20789926, "min": 0.12172694124000001, "max": 0.16274702724, "times": [ 0.13256413724000002, 0.16274702724, 0.13479302724, 0.12172694124000001, 0.14269577724000002, 0.12953047424000003, 0.13417019524, 0.14712134424, 0.13916210824000003, 0.12409607224000002, 0.14662673224, 0.13220223224000002, 0.12414616724000002, 0.14173024424000003, 0.13072793824 ], "exit_codes": [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ] } ] } ```