wafHook: run waf without explicit python interpreter (#396641)

pkgs/by-name/wa/waf/setup-hook.sh

@@ -3,7 +3,9 @@
 wafConfigurePhase() {
     runHook preConfigure
 
-    if ! [ -f "${wafPath:=./waf}" ]; then
+    if [ -f "${wafPath:=./waf}" ]; then
+        patchShebangs --build "${wafPath}"
+    else
         wafPath="@waf@/bin/waf"
     fi
 
@@ -19,7 +21,7 @@ wafConfigurePhase() {
     concatTo flagsArray wafConfigureFlags wafConfigureFlagsArray wafConfigureTargets=configure
 
     echoCmd 'waf configure flags' "${flagsArray[@]}"
-    python "$wafPath" "${flagsArray[@]}"
+    "$wafPath" "${flagsArray[@]}"
 
     if ! [[ -v enableParallelBuilding ]]; then
         enableParallelBuilding=1
@@ -41,7 +43,7 @@ wafBuildPhase () {
     concatTo flagsArray wafFlags wafFlagsArray wafBuildFlags wafBuildFlagsArray wafBuildTargets=build
 
     echoCmd 'waf build flags' "${flagsArray[@]}"
-    python "$wafPath" "${flagsArray[@]}"
+    "$wafPath" "${flagsArray[@]}"
 
     runHook postBuild
 }
@@ -57,7 +59,7 @@ wafInstallPhase() {
     concatTo flagsArray wafFlags wafFlagsArray wafInstallFlags wafInstallFlagsArray wafInstallTargets=install
 
     echoCmd 'waf install flags' "${flagsArray[@]}"
-    python "$wafPath" "${flagsArray[@]}"
+    "$wafPath" "${flagsArray[@]}"
 
     runHook postInstall
 }