fix: gracefully handle closed stderr

[reubeno]

Applies the fix from #873 to stderr as well.

Fixes #874

[github-actions]

Test Results

    3 files     26 suites   9m 9s ⏱️
1 452 tests 1 452 ✅ 0 💤 0 ❌
4 336 runs  4 336 ✅ 0 💤 0 ❌

Results for commit 5c90595.

[github-actions]

Performance Benchmark Report

Benchmark name	Baseline (μs)	Test/PR (μs)	Delta (μs)	Delta %
clone_shell_object	17.53 μs	17.75 μs	0.22 μs	🟠 +1.26%
eval_arithmetic	0.14 μs	0.15 μs	0.00 μs	⚪ Unchanged
expand_one_string	1.62 μs	1.65 μs	0.03 μs	⚪ Unchanged
for_loop	22.70 μs	22.82 μs	0.12 μs	⚪ Unchanged
function_call	2.29 μs	2.26 μs	-0.03 μs	⚪ Unchanged
instantiate_shell	54.06 μs	54.66 μs	0.60 μs	🟠 +1.11%
instantiate_shell_with_init_scripts	24306.67 μs	24299.67 μs	-7.00 μs	⚪ Unchanged
parse_bash_completion	2005.19 μs	2017.18 μs	11.99 μs	⚪ Unchanged
parse_sample_script	1.93 μs	1.99 μs	0.06 μs	🟠 +3.32%
run_echo_builtin_command	15.13 μs	15.17 μs	0.03 μs	⚪ Unchanged
tokenize_sample_script	3.46 μs	3.46 μs	-0.00 μs	⚪ Unchanged

Code Coverage Report: Only Changed Files listed

Package	Base Coverage	New Coverage	Difference
brush-core/src/expansion.rs	🟢 95.22%	🟢 95.14%	🔴 -0.08%
brush-core/src/interp.rs	🟢 93.16%	🟢 93.18%	🟢 0.02%
Overall Coverage	🟢 74.09%	🟢 74.09%	⚪ 0%

Minimum allowed coverage is 70%, this run produced 74.09%

Test Summary: bash-completion test suite

Outcome	Count	Percentage
✅ Pass	1544	73.21
❗️ Error	21	1.00
❌ Fail	190	9.01
⏩ Skip	339	16.07
❎ Expected Fail	13	0.62
✔️ Unexpected Pass	2	0.09
📊 Total	2109	100.00