Fix try init in bash when launched from fish shell (#4640)

The try command detects shell type from $SHELL variable. When bash is
launched from fish, $SHELL is still set to /usr/bin/fish, causing try
to output fish syntax which fails in bash with syntax errors.

Explicitly set SHELL=/bin/bash for the try init call to ensure correct
shell detection.

default/bash/init

@@ -14,7 +14,7 @@ if command -v zoxide &> /dev/null; then
 fi
 
 if command -v try &> /dev/null; then
-  eval "$(try init ~/Work/tries)"
+  eval "$(SHELL=/bin/bash try init ~/Work/tries)"
 fi
 
 if command -v fzf &> /dev/null; then