Update issue text for EXT_texture_shadow_lod (#634)

One issue referred to a bug that has now been fixed, so is no longer
relevant, so this text is removed.

An additional issue is added describing which stages the bias variants
are added to. The normative text was already correct but this may aid
clarity.

extensions/EXT/EXT_texture_shadow_lod.txt

@@ -25,8 +25,8 @@ Status
 
 Version
 
-    Last Modified Date: June 3, 2019
-    Revision:   2
+    Last Modified Date: September 26, 2024
+    Revision:   3
 
 Number
 
@@ -134,13 +134,9 @@ Issues
          family of missing functions is deserving of its own extension.
 
          textureGrad() is missing support for samplerCubeArrayShadow in both
-         the GLSL and ESSL specifications, and is also missing support for
-         gsampler2DArray variants only in the ESSL specification.  The
-         samplerCubeArrayShadow variant is not included in this extension
-         because not all vendors can easily support the additional parameter
-         beyond the gradients.  The missing gsampler2DArray variants in ESSL
-         are not added because they are unrelated to shadow types and thus
-         outside the scope of this extension.
+         the GLSL and ESSL specifications.  This variant is not included in this
+         extension because not all vendors can easily support the additional
+         parameter beyond the gradients.
 
     (2)  The GLSL specification already contains a definition for
          textureOffset() with sampler2DArrayShadow; does this mean only the optional
@@ -150,8 +146,19 @@ Issues
          not have either the non-bias or bias variants of this function so both
          variants should be defined according to this extension.
 
+    (3) To which stages are bias variants added?
+
+         RESOLVED: The bias variants are added consistently with the core texture
+         functions. This means that the bias variants are supported only in fragment
+         shaders unless another extension, such as GL_NV_compute_shader_derivatives,
+         expands support for these variants to other stages.
+
 Revision History
 
+    Revision 3
+    - Update issue text that referred to a bug which has been fixed.
+    - Add an issue clarifying the supported stages for bias-variant functions.
+
     Revision 2
     - Minor correction on contributor name.