Remove the BETA status for torch.linalg (#58043)

Summary:
We are ready to move to the new stage for our `torch.linalg` module, which is stable (or STABLE?).

Ref. https://github.com/pytorch/pytorch/issues/42666

Pull Request resolved: https://github.com/pytorch/pytorch/pull/58043

Reviewed By: ngimel

Differential Revision: D28356172

Pulled By: mruberry

fbshipit-source-id: e2c1effa79b9635b2ef0a820a03a0685105042bd
diff --git a/docs/source/linalg.rst b/docs/source/linalg.rst
index 757e824..ed63aed 100644
--- a/docs/source/linalg.rst
+++ b/docs/source/linalg.rst
@@ -6,10 +6,6 @@
 
 Common linear algebra operations.
 
-This module is in BETA. New functions are still being added, and some
-functions may change in future PyTorch releases. See the documentation of each
-function for details.
-
 .. automodule:: torch.linalg
 .. currentmodule:: torch.linalg