[doc] Remove "forward" and "predict_step" from extras.txt

Lightning API was fixed so these can be removed.

doc/extras.inv

@@ -2,5 +2,5 @@
 # Project: extras
 # Version: stable
 # The remainder of this file is compressed using zlib.
-xڭA
-1E[[R
MH2A\.{OItņTLR+.$Uns<lI	ԟ2hl1iB$`g/aG%<XU)ibłw/
\ No newline at end of file
+xEA0;Wbq
(ĖmS*Yg󛌸EZ-2T^%dw
@#GAcZTiEt=qI
+9ȊǷݱi>T>

doc/extras.txt

@@ -3,6 +3,4 @@
 # Version: stable
 # The remainder of this file is compressed using zlib.
 torchvision.transforms py:module 1 https://pytorch.org/vision/stable/transforms.html -
-lightning.pytorch.core.module.LightningModule.forward py:method 1 api/lightning.pytorch.core.LightningModule.html#$ -
-lightning.pytorch.core.module.LightningModule.predict_step py:method 1 api/lightning.pytorch.core.LightningModule.html#$ -
 optimizer_step py:method 1 api/lightning.pytorch.core.LightningModule.html#$ -