Remove EDGEDB_USER and EDGEDB_PASSWORD from README.md

[fmoor]

This is more of a question than a proposed change. I noticed that EDGEDB_USER is not in a single test, but is mentioned as a supported environment variable. Are we supposed to support it?

EDGEDB_PASSWORD is mentioned in the tests, but it is always either ignored in the result or it is the DSN option password_env target like in this test:

shared-client-testcases/tests/override/other.jsonc

Lines 1602 to 1616 in e395996

	{
	"env": {
	"EDGEDB_PASSWORD": "password"
	},
	"name": "test_78",
	"opts": {
	"dsn": "edgedb://testuser@localhost/db?password_env=EDGEDB_PASSWORD"
	},
	"result": {
	"branch": "db",
	"database": "db",
	"password": "password",
	"user": "testuser"
	}
	},

There are no tests that assert that EDGEDB_PASSWORD is recognized by the client on its own. Are there any cases when EDGEDB_PASSWORD should be recognized by the client without the password_env DSN option?

My knee jerk assumption is that they should both be supported, but I'm not sure I remember all the rules and I'm not sure they are written down anywhere.

[msullivan]

The Python bindings support EDGEDB_USER and EDGEDB_PASSWORD (and GEL_USER and GEL_PASSWORD).
My inclination is that they should be supported.

[msullivan]

I think we should test and support them

[fmoor]

closing in favor of #43