[epiphany] Remove the valgrind instructions

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 646544c089ed88e579e47bb34f977f95a3336d41
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Thu Feb 17 20:09:47 2022 +0000

    Remove the valgrind instructions
    
    No longer needed since https://bugs.webkit.org/show_bug.cgi?id=230460
    
    I'm not sure when Gigacage stopped crashing valgrind, but it works nowadays.
    
    GSlice also has its own code to detect valgrind nowadays. So we no longer need anything special.

 HACKING.md | 10 ----------
 1 file changed, 10 deletions(-)
---
diff --git a/HACKING.md b/HACKING.md
index 8f935fbf5..c1150c284 100644
--- a/HACKING.md
+++ b/HACKING.md
@@ -228,13 +228,3 @@ filename. E.g. `export EPHY_PROFILE_MODULES=ephy-window.c:ephy-autocompletion.c`
 The special profiling module `all` enables all profiling modules.
 
 Use `START_PROFILER STOP_PROFILER` macros to profile pieces of code.
-
-## valgrind
-
-To use valgrind, you must use environment variables to disable WebKit's sandbox
-and JavaScriptCore's Gigacage. You will also want to disable GSlice and bmalloc
-in order to force all allocations though the system allocator:
-
-```
-WEBKIT_FORCE_SANDBOX=0 GIGACAGE_ENABLED=0 G_SLICE=always-malloc Malloc=1 valgrind --track-origins=yes 
--leak-check=full epiphany
-```