macOS: mute tput warnings

tput warns you when running with no attached terminal; eg. GitHub CI.
Redirects warnings to /dev/null

tools/osx/macosx_bundle.sh

@@ -9,11 +9,11 @@
 # - GTK_PREFIX
 
 # Formatting
-fNormal="$(tput sgr0)"
-fBold="$(tput bold)"
+fNormal="$(tput sgr0)" >/dev/null 2>&1
+fBold="$(tput bold)" >/dev/null 2>&1
 # Colors depend upon the user's terminal emulator color scheme - what is readable for you may be not readable for someone else.
-fMagenta="$(tput setaf 5)"
-fRed="$(tput setaf 1)"
+fMagenta="$(tput setaf 5)" >/dev/null 2>&1
+fRed="$(tput setaf 1)" >/dev/null 2>&1
 
 function msg {
     printf "\\n${fBold}-- %s${fNormal}\\n" "${@}"