[Toybox] mkpasswd crashes in github ci

[enh]

doesn't affect android's build because we don't build mkpasswd, but
the mkpasswd tests are failing on github with sigsegv:

scripts/runtest.sh: line 139: 11537 Segmentation fault      (core
dumped) "/home/runner/work/toybox/toybox/generated/testdir/mkpasswd"
-P0 -mmd5 -S abcdefgh
FAIL: mkpasswd md5
echo -ne 'password' |
'"/home/runner/work/toybox/toybox/generated/testdir/mkpasswd" -P0
-mmd5 -S abcdefgh'
--- expected 2025-05-27 20:19:58.154451309 +0000
+++ actual 2025-05-27 20:19:58.158451296 +0000
@@ -1 +0,0 @@
-$1$abcdefgh$G//4keteveJp0qb8z2DxG/
scripts/runtest.sh: line 139: 11551 Segmentation fault      (core
dumped) "/home/runner/work/toybox/toybox/generated/testdir/mkpasswd"
-P0 -msha-256 -S abcdefgh
FAIL: mkpasswd sha256-8
echo -ne 'password' |
'"/home/runner/work/toybox/toybox/generated/testdir/mkpasswd" -P0
-msha-256 -S abcdefgh'
--- expected 2025-05-27 20:19:58.390450518 +0000
+++ actual 2025-05-27 20:19:58.395450501 +0000
@@ -1 +0,0 @@
-$5$abcdefgh$ZLdkj8mkc2XVSrPVjskDAgZPGjtj1VGVaa1aUkrMTU/
scripts/runtest.sh: line 139: 11567 Segmentation fault      (core
dumped) "/home/runner/work/toybox/toybox/generated/testdir/mkpasswd"
-P0 -msha-256 -S ./Aa0Bb1Cc2Dd3Ee
FAIL: mkpasswd sha256-16
echo -ne 'password' |
'"/home/runner/work/toybox/toybox/generated/testdir/mkpasswd" -P0
-msha-256 -S ./Aa0Bb1Cc2Dd3Ee'
--- expected 2025-05-27 20:19:58.582449863 +0000
+++ actual 2025-05-27 20:19:58.587449845 +0000
@@ -1 +0,0 @@
-$5$./Aa0Bb1Cc2Dd3Ee$5iXcesTggTRGvAAa3cWlpxmUqNGOeQh/iO3Furo4y/D
scripts/runtest.sh: line 139: 11584 Segmentation fault      (core
dumped) "/home/runner/work/toybox/toybox/generated/testdir/mkpasswd"
-P0 -msha-512 -S abcdefgh
FAIL: mkpasswd sha512-8
echo -ne 'password' |
'"/home/runner/work/toybox/toybox/generated/testdir/mkpasswd" -P0
-msha-512 -S abcdefgh'
--- expected 2025-05-27 20:19:58.772449173 +0000
+++ actual 2025-05-27 20:19:58.777449155 +0000
@@ -1 +0,0 @@
scripts/runtest.sh: line 139: 11598 Segmentation fault      (core
dumped) "/home/runner/work/toybox/toybox/generated/testdir/mkpasswd"
-P0 -msha-512 -S ./Aa0Bb1Cc2Dd3Ee
-$6$abcdefgh$yVfUwsw5T.JApa8POvClA1pQ5peiq97DUNyXCZN5IrF.BMSkiaLQ5kvpuEm/VQ1Tvh/KV2TcaWh8qinoW5dhA1
FAIL: mkpasswd sha512-16
echo -ne 'password' |
'"/home/runner/work/toybox/toybox/generated/testdir/mkpasswd" -P0
-msha-512 -S ./Aa0Bb1Cc2Dd3Ee'
--- expected 2025-05-27 20:19:58.965448472 +0000
+++ actual 2025-05-27 20:19:58.969448457 +0000
@@ -1 +0,0 @@
-$6$./Aa0Bb1Cc2Dd3Ee$PvmedaPf329sM25Jn2jv3MsfK9DaDh6tyVtJucp35A/Lmrtp9g1Ab35Mr59pkuMU3QJlbXYoWJFaxyD4OwIZ60