Remove redundant cooldown ecosystem list from README

The supported registries table already shows which ecosystems have
cooldown support. The inline list kept getting out of sync.

Author: andrew

README.md

@@ -18,9 +18,7 @@ cooldown:
 
 A 3-day cooldown means that when `lodash` publishes version `4.18.0`, your builds keep using `4.17.21` until 3 days have passed. If the new release turns out to be compromised, you were never exposed.
 
-Resolution order: package override, then ecosystem override, then global default. This lets you set a conservative default and carve out exceptions for packages where you need faster updates.
-
-Currently works with npm, PyPI, pub.dev, Composer, and Cargo, which all include publish timestamps in their metadata. See [docs/configuration.md](docs/configuration.md) for the full config reference.
+Resolution order: package override, then ecosystem override, then global default. This lets you set a conservative default and carve out exceptions for packages where you need faster updates. See [docs/configuration.md](docs/configuration.md) for the full config reference.
 
 ## Supported Registries