Fix the CI

[bquorning]

On opening #61 I realized that CI was failing for unrelated reasons, and found a few things to fix.

On the legacy builds, actions/checkout@v3 (and v4 too if you try) fail with

/__e/node20/bin/node: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.27' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.25' not found (required by /__e/node20/bin/node)

See also actions/checkout#1590 (people reporting it broken with v3 since August 16th or so).

[pirj]

@JonRowe I don’t have merge rights here.