ghcjs: Intermittent failures in test process005

Failure output looks like:

--- "/builds/ghc/ghc/tmp/ghctest-fr3j1xf8/test   spaces/testsuite/tests/concurrent/should_run/conc015.run/conc015.stdout.normalised"    2024-01-15 21:11:58.210263802 +0000
+++ "/builds/ghc/ghc/tmp/ghctest-fr3j1xf8/test   spaces/testsuite/tests/concurrent/should_run/conc015.run/conc015.run.stdout.normalised"        2024-01-15 21:11:58.210263802 +00
00
@@ -1,5 +1,3 @@
 Unmasked
 MaskedInterruptible
-caught1: foo
-MaskedInterruptible
-caught2: bar
+caught1: bar
--- "/builds/ghc/ghc/tmp/ghctest-fr3j1xf8/test   spaces/libraries/process/tests/process005.run/process005.stdout.normalised"    2024-01-15 21:51:02.261279603 +0000
+++ "/builds/ghc/ghc/tmp/ghctest-fr3j1xf8/test   spaces/libraries/process/tests/process005.run/process005.run.stdout.normalised"        2024-01-15 21:51:02.261279603 +0000
@@ -1,4 +1 @@
-testing
-testing
-123
 end

Incidents in the last two weeks:

json->>'id'	json->>'status'	json->>'ref'	json->>'name'	json->>'web_url'	json->>'runner.description'	date(json->>'created_at')
1757981	failed	refs/merge-requests/11953/head	x86_64-linux-deb11-int_native-cross_javascript-unknown-ghcjs-validate	https://gitlab.haskell.org/ghc/ghc/-/jobs/1757981	x86_64-linux-7.zw3rk_x86_64-linux-7_db038e4e1623	2024-01-22
1757822	failed	master	nightly-x86_64-linux-deb11-int_native-cross_javascript-unknown-ghcjs-validate	https://gitlab.haskell.org/ghc/ghc/-/jobs/1757822	x86_64-linux-7.zw3rk_x86_64-linux-7_db038e4e1623	2024-01-22
1755460	failed	refs/merge-requests/11933/head	x86_64-linux-deb11-int_native-cross_javascript-unknown-ghcjs-validate	https://gitlab.haskell.org/ghc/ghc/-/jobs/1755460	x86_64-linux-2.zw3rk_x86_64-linux-2_d292a225d2eb	2024-01-18
1753972	failed	refs/merge-requests/11929/head	x86_64-linux-deb11-int_native-cross_javascript-unknown-ghcjs-validate	https://gitlab.haskell.org/ghc/ghc/-/jobs/1753972	x86_64-linux-2.zw3rk_x86_64-linux-2_d292a225d2eb	2024-01-16
1753044	failed	refs/merge-requests/11921/head	x86_64-linux-deb11-int_native-cross_javascript-unknown-ghcjs-validate	https://gitlab.haskell.org/ghc/ghc/-/jobs/1753044	x86_64-linux-6.zw3rk_x86_64-linux-6_db038e4e1623	2024-01-15
1750068	failed	refs/merge-requests/11894/head	x86_64-linux-deb11-int_native-cross_javascript-unknown-ghcjs-validate	https://gitlab.haskell.org/ghc/ghc/-/jobs/1750068	x86_64-linux-6.zw3rk_x86_64-linux-6_db038e4e1623	2024-01-11