Drop p-limit internally

[dcousens]

This pull request should remove the use of p-limit internally for limiting Prisma engine operations.
prisma/prisma#2955 has been resolved, and - at least as documented - this was the only reason this approach was taken.

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[dcousens]

Although this pull request removes the internal p-limit calls, and the aforementioned issue prisma/prisma#2955 has been closed, unfortunately the problems with sqlite don't end with that.

As reported in the following issues to prisma:

• SQLite times out during query execution when using Promise.all() / concurrent prisma/prisma#9562
• Improve the error when SQLite database file is locked prisma/prisma#10403
• ConnectionError(Timed out during query execution.) error when using Promise.all for SQLite prisma/prisma#11789

To prevent broken behaviour, especially in our tests, we need Prisma to internally queue the sqlite "connections".
The existing p-limit implementation used a global p-limit that prevented many tests running at the same time, this removes that restriction by ensuring the tests do not need need to run sequentially and instead relying on connection_limit=1 to prevent connection issues.

[dcousens]

Shortened the strings to work within database limitations

[dcousens]

This is incompatible with how we are using Prisma now, and probably Prisma 5 too

[dcousens]

This was completely broken