Fix `JobStore.from_file` docstring

[Andrew-S-Rosen]

Fixes a minor typo I stumbled upon in #542.

[codecov[bot]]

Codecov Report

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

Comparison is base (8e5a3fe) 99.42% compared to head (dac7d87) 99.42%. Report is 10 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #543 +/- ## ======================================= Coverage 99.42% 99.42% ======================================= Files 21 21 Lines 1556 1556 Branches 422 422 ======================================= Hits 1547 1547 Misses 9 9 ``` | [Files](https://app.codecov.io/gh/materialsproject/jobflow/pull/543?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=materialsproject) | Coverage Δ | | |---|---|---| | [src/jobflow/core/store.py](https://app.codecov.io/gh/materialsproject/jobflow/pull/543?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=materialsproject#diff-c3JjL2pvYmZsb3cvY29yZS9zdG9yZS5weQ==) | `100.00% <ø> (ø)` | |

[utf]

Thanks!