creating last_green binaries is a cross repo effort.

The work of the server is as follows:

For every OS/arch mongod binary we want mongot-main to run 10gen/mongot tests with, the server will add a cron only variant that will produce that OS/arch mongod last_green_candidate binary and run all search tests defined on 10gen/mongod with said binary. The server will add these variants to the mongodb-mongo-* evergreen projects and to db-contrib-tool's setup-repro-env-config.yml so that mongot-main can download the new variants' last_green_candidate binaries.

The work of mongot is as follows:

Add a project trigger to mongot-main per cron only variant per mongodb-mongo-* evergreen project that step 1 introduced. For the time being, only master version is needed. Define the project trigger to run when the given variants succeed (eg the search tests on 10gen/mongo pass).

The commit hash associated with the triggered event should be accessible via `{$trigger_revision}` and the server version via `${trigger_branch}`. 

To download each variant's last_green_candidate, you will need to use db-contrib-tool. The command should look something like 

db-contrib-tool setup-repro-env --variant AL2023-x86-mongot-integration-cron-only {$trigger_revision}

where AL2023-x86-mongot-integration-cron-only is an example variant name.

When mongot verifies that last_green_candidate binary of X variant passes, mongot can push that binary to a hard-coded/not changing s3 last_green_<os>_<arch> link that 10gen/mongot pre-commit tests pull from.