Don't start services by default

The Python Black formatter includes a local web server feature.
The Homebrew formula for Black starts `blackd` by default, but this is
not necessary. The VSCode Black formatter extension uses LSP instead of
`blackd`, and there are no other uses of `blackd` on the system.

The Homebrew formula for PostgreSQL starts the server by default, but
this is not always needed. The service can be started on-demand with
`brew services run postgresql@<VERSION>`.

Running services can be stopped with `brew services stop --all`.

https://black.readthedocs.io/en/stable/usage_and_configuration/black_as_a_server.html
https://docs.brew.sh/Manpage#services-subcommand
https://github.com/Homebrew/homebrew-core/blob/3a8a9cb5fa04640233243b0dfa4550a48f0548f2/Formula/b/black.rb
https://github.com/microsoft/vscode-black-formatter
microsoft/vscode-python#3336

Brewfile

@@ -4,7 +4,7 @@ tap "homebrew/services"
 
 brew "awscli"
 brew "bash"
-brew "black", restart_service: :changed
+brew "black", restart_service: false, start_service: false
 brew "ffmpeg"
 brew "findutils"
 brew "flake8"
@@ -35,7 +35,7 @@ brew "pinentry"
 # brew "pinentry-mac"
 brew "pipx"
 brew "pnpm"
-brew "postgresql@16", restart_service: :changed
+brew "postgresql@16", restart_service: false, start_service: false
 brew "pre-commit"
 brew "prettier"
 brew "python"