use sys.executable, fix quotes

test/test.py

diff --git a/test/test.py b/test/test.py
index 9b9b596..b3170dc 100755
--- a/test/test.py
+++ b/test/test.py
@@ -10,7 +10,7 @@
 
 WINDOWS = sys.platform.startswith('win')
 MACOS = sys.platform == 'darwin'
-MACOS_ARM64 = MACOS and platform.machine() == "arm64"
+MACOS_ARM64 = MACOS and platform.machine() == 'arm64'
 
 emconfig = os.path.abspath('.emscripten')
 assert os.path.exists(emconfig)
@@ -200,7 +200,7 @@
 
   def test_specific_version(self):
     if MACOS_ARM64:
-      self.skipTest("Old sdk versions do not have ARM64 binaries")
+      self.skipTest('Old sdk versions do not have ARM64 binaries')
     print('test specific release (new, short name)')
     run_emsdk('install 1.38.33')
     print('another install, but no need for re-download')
@@ -209,7 +209,7 @@
 
   def test_specific_version_full(self):
     if MACOS_ARM64:
-      self.skipTest("Old sdk versions do not have ARM64 binaries")
+      self.skipTest('Old sdk versions do not have ARM64 binaries')
     print('test specific release (new, full name)')
     run_emsdk('install sdk-1.38.33-64bit')
     run_emsdk('activate sdk-1.38.33-64bit')
@@ -226,7 +226,7 @@
   def test_no_32bit(self):
     print('test 32-bit error')
     emsdk_hacked = hack_emsdk('not is_os_64bit()', 'True')
-    failing_call_with_output('python3 %s install latest' % emsdk_hacked, 'this tool is only provided for 64-bit OSes')
+    failing_call_with_output(f'{sys.executable} {emsdk_hacked} install latest', 'this tool is only provided for 64-bit OSes')
     os.remove(emsdk_hacked)
 
   def test_update_no_git(self):