attributes.sh regressions on Alpine Linux

[McDutchie]

This now fails on Alpine:

test attributes begins at 2026-04-17+20:37:39
	attributes.sh[381]: FAIL: [ ''  'TZ=PST8PDT'  '' ] env sequence failed -- expected '03 00 03', got '00 18 00'
	attributes.sh[381]: FAIL: [ ''  'TZ=PST8PDT'  'TZ=EST5EDT' ] env sequence failed -- expected '03 00 03', got '00 18 00'
	attributes.sh[381]: FAIL: [ 'TZ=EST5EDT'  'TZ=PST8PDT'  'TZ=EST5EDT' ] env sequence failed -- expected '03 00 03', got '00 18 00'
	attributes.sh[381]: FAIL: [ 'TZ=PST8PDT'  ''  'TZ=PST8PDT' ] env sequence failed -- expected '00 03 00', got '18 00 18'
	attributes.sh[381]: FAIL: [ 'TZ=PST8PDT'  'TZ=EST5EDT'  'TZ=PST8PDT' ] env sequence failed -- expected '00 03 00', got '18 00 18'
	attributes.sh[381]: FAIL: [ 'foo=bar'  'TZ=PST8PDT'  'TZ=EST5EDT' ] env sequence failed -- expected '03 00 03', got '00 18 00'
test attributes failed at 2026-04-17+20:37:39 with exit code 6 [ 169 tests 6 errors ]

I did a git bisect. The tests start failing as of commit f15e2c4 (dev) a.k.a. e08e20b (1.0).