Fix macOS CI

[iamed2]

There are now two macOS jobs (M1 and x64) and they fail the same way that the others fail now:

• https://github.com/JuliaDatabases/LibPQ.jl/actions/runs/10307403301/job/28532612280?pr=295
• https://github.com/JuliaDatabases/LibPQ.jl/actions/runs/10307403301/job/28532611996?pr=295