docs: deprecate deepExtract (#13487)

docs/usage/configuration-options.md

@@ -431,6 +431,8 @@ Note: make sure not to mix this up with the term `compatibility`, which Renovate
 
 ## deepExtract
 
+Note: the `deepExtract` configuration option is deprecated, and will be removed in a future Renovate release.
+
 If configured to `true`, then dependency extraction will be done using the relevant package manager instead of JavaScript-based parsing.
 
 This option applies only to the `gradle` manager.

docs/usage/java.md

@@ -80,6 +80,7 @@ Renovate will search repositories for all `pom.xml` files and processes them ind
 ## Custom registry support, and authentication
 
 Unless using `deepExtract`, Renovate does not make use of authentication credentials available to Gradle.
+Note: the `deepExtract` configuration option is deprecated, and will be removed in a future Renovate release.
 
 The manager for Gradle makes use of the `maven` datasource.
 Renovate can be configured to access additional repositories and access repositories authenticated.

lib/manager/gradle/readme.md

 The `gradle` manager's default behavior uses a custom parser written in JavaScript, similar to many others managers.
 It was initially known as `gradle-lite` but is now integrated into the `gradle` manager and used as default.
 
+Note: the `deepExtract` configuration option is deprecated, and will be removed in a future Renovate release.
+
 If `deepExtract` is configured to `true`, Renovate instead extracts Gradle dependencies by calling a custom Gradle script.
 The `gradle` binary is then used to extract Maven-type dependencies.