Merge pull request swiftlang#36648 from edymtt/use-python3-to-test-installable-package

[build] use python3 when testing installable package

Author: shahmishal

utils/build-script-impl

@@ -3246,11 +3246,11 @@ function build_and_test_installable_package() {
             with_pushd "${PKG_TESTS_SANDBOX_PARENT}" \
                 call tar xzf "${package_for_host}"
 
-            if python -c "import psutil" ; then
+            if python3 -c "import psutil" ; then
               TIMEOUT_ARGS=--timeout=1200 # 20 minutes
             fi
             with_pushd "${PKG_TESTS_SOURCE_DIR}" \
-                call python "${LIT_EXECUTABLE_PATH}" . -sv --param package-path="${PKG_TESTS_SANDBOX}" --param test-exec-root="${PKG_TESTS_TEMPS}" --param llvm-bin-dir="${LLVM_BIN_DIR}" ${TIMEOUT_ARGS}
+                call python3 "${LIT_EXECUTABLE_PATH}" . -sv --param package-path="${PKG_TESTS_SANDBOX}" --param test-exec-root="${PKG_TESTS_TEMPS}" --param llvm-bin-dir="${LLVM_BIN_DIR}" ${TIMEOUT_ARGS}
         fi
     fi
 }