When we run the HGE server inside the test harness, it needs to run with
an admin secret for some tests to make sense. This tags each test that
requires an admin secret with `pytest.mark.admin_secret`, which then
generates a UUID and injects that into both the server and the test case
(if required).
It also simplifies the way the test harness picks up an existing admin
secret, allowing it to use the environment variable instead of requiring
it via a parameter.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6120
GitOrigin-RevId: 55c5b9e8c99bdad9c8304098444ddb9516749a2c
Rename the admin secret key header used to access GraphQL engine from X-Hasura-Access-Key to X-Hasura-Admin-Secret.
Server CLI and console all support the older flag but marks it as deprecated.
