chore: downgrade homedir

[reubeno]

As #660 calls out, the current version of homedir being used in this project requires an MSRV of 1.88+. This wasn't obvious when we upgraded from homedir 0.3.4 to 0.3.5 (although 0.3.6 now correctly marks its MSRV). Until we're ready to upgrade MSRV, we're downgrading homedir so we can continue to build cleanly on 1.85+.

[github-actions]

Test Results

    3 files     20 suites   4m 28s ⏱️
  873 tests   873 ✅ 0 💤 0 ❌
2 599 runs  2 599 ✅ 0 💤 0 ❌

Results for commit e831ae8.

♻️ This comment has been updated with latest results.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
clone_shell_object	17.87 μs	17.76 μs	-0.11 μs	🟢 -0.62%
eval_arithmetic	0.15 μs	0.15 μs	-0.00 μs	⚪ Unchanged
expand_one_string	1.87 μs	1.83 μs	-0.03 μs	⚪ Unchanged
for_loop	22.37 μs	22.29 μs	-0.08 μs	⚪ Unchanged
function_call	2.37 μs	2.40 μs	0.03 μs	⚪ Unchanged
instantiate_shell	54.52 μs	54.95 μs	0.43 μs	⚪ Unchanged
instantiate_shell_with_init_scripts	22254.11 μs	22254.38 μs	0.27 μs	⚪ Unchanged
parse_bash_completion	1717.77 μs	1725.29 μs	7.51 μs	⚪ Unchanged
parse_sample_script	1.90 μs	1.90 μs	0.00 μs	⚪ Unchanged
run_echo_builtin_command	15.08 μs	15.08 μs	-0.00 μs	⚪ Unchanged
run_one_external_command	4712.46 μs	7845.17 μs	3132.71 μs	🟠 +66.48%
tokenize_sample_script	2.72 μs	2.71 μs	-0.01 μs	⚪ Unchanged

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/builtins/return_.rs	🟢 94.12%	🟢 93.33%	🔴 -0.79%
brush-core/src/jobs.rs	🔴 37.16%	🔴 43.58%	🟢 6.42%
brush-core/src/sys/unix/signal.rs	🟠 56.36%	🟠 60%	🟢 3.64%
Overall Coverage	🟢 72%	🟢 72.09%	🟢 0.09%

Minimum allowed coverage is 70%, this run produced 72.09%

Test Summary: bash-completion test suite

Outcome	Count	Percentage
✅ Pass	1312	62.21
❗️ Error	235	11.14
❌ Fail	188	8.91
⏩ Skip	359	17.02
❎ Expected Fail	15	0.71
📊 Total	2109	100.00