Update bug_report_spirv.md (microsoft#6988)

Removes shader playground link. Shader playground hasn't been updated
since earlier this year, hence DXC version is very stale.

Author: Keenuts

.github/ISSUE_TEMPLATE/bug_report_spirv.md

@@ -12,11 +12,11 @@ assignees: ''
 
 **Steps to Reproduce**
 <!--- Provide a description of how to reproduce the error. If possible please 
-provide source and tool command line options. If the issue reproduces on
-Compiler Explorer (https://godbolt.org/) or Shader Playground
-(https://shader-playground.timjones.io/) please provide a link. If the source is
-split across multiple files, please preprocess into a single file using DXC's 
-command line `-P -Fi <path>`. --->
+provide source and tool command line options, or if the issue reproduces on
+Compiler Explorer (https://godbolt.org/), please provide a link.
+If the source is split across multiple files, please preprocess into a single file using DXC's 
+command line `-P -Fi <path>`.
+ --->
 
 
 **Actual Behavior**