docs: Correct typo (#10489)

The example uses the 'pip' install method but the explanation suggests
it should have used 'pip'.

Signed-off-by: Stephen Finucane <[email protected]>

Author: stephenfin

docs/user/config-file/v2.rst

@@ -221,7 +221,7 @@ Example:
          path: .
          extra_requirements:
            - docs
-       - method: pip
+       - method: setuptools
          path: package
 
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