chore: Rework testing to reduce time spent and to remove the hatch run cov command

[jason-famedly]

Tests were taking to long. Let's speed them up!

Before, we ran unit tests and collected coverage with the command hatch run cov. This ran the tests on a single process/thread and (in CI) tested against both SQLite and Postgres as a matrix, consecutively.

Now, the built-in hatch test command can be used for the same purpose.
hatch test will run all tests without coverage on a single process/thread
Add -p as an option to run all tests using all available cores/threads of a CPU.
Add -c as an option to collect coverage data.

These are interchangeable. Previously, on my machine these tests with coverage took just over 2 minutes, now it is just over 30 seconds. Without coverage is even faster.

SQLite testing will be the default. Running in Postgres is only slightly more labor intensive. A Postgres installation is required of course(see the python.yml testing workflow for a quick example) and then add to the front of your command the ENV variables that the testing suite will automatically look for:
SYNAPSE_POSTGRES=1 SYNAPSE_POSTGRES_USER=<theDatabaseUser> SYNAPSE_POSTGRES_PASSWORD=<theDBUsersPassword> hatch test

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.61%. Comparing base (90f0f8d) to head (5d25743).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #131      +/-   ##
==========================================
- Coverage   97.24%   95.61%   -1.63%     
==========================================
  Files           7        7              
  Lines         798      798              
  Branches      118      118              
==========================================
- Hits          776      763      -13     
  Misses         22       22              
- Partials        0       13      +13     

see 2 files with indirect coverage changes

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[jason-famedly]

This will need the required test checks adjusted before it can be merged, as they will have changed

[FrenchGithubUser]

Looks good to me!