gh-104780: Remove 2to3 program and lib2to3 module (#104781)

* Remove the Tools/scripts/2to3 script.
* Remove the Lib/test/test_lib2to3/ directory.
* Doc/tools/extensions/pyspecific.py: remove the "2to3fixer" object
  type.
* Makefile and PC/layout/main.py no longer compile lib2to3 grammar
  files.
* Update Makefile for 2to3 removal.

Mac/BuildScript/scripts/postflight.framework

@@ -8,12 +8,12 @@ FWK="/Library/Frameworks/Python.framework/Versions/@PYVER@"
 
 "${FWK}/bin/python@PYVER@" -E -s -Wi \
     "${FWK}/lib/python${PYVER}/compileall.py" -q -j0 \
-    -f -x 'bad_coding|badsyntax|site-packages|test/test_lib2to3/data' \
+    -f -x 'bad_coding|badsyntax|site-packages' \
     "${FWK}/lib/python${PYVER}"
 
 "${FWK}/bin/python@PYVER@" -E -s -Wi -O \
     "${FWK}/lib/python${PYVER}/compileall.py" -q -j0 \
-    -f -x 'bad_coding|badsyntax|site-packages|test/test_lib2to3/data' \
+    -f -x 'bad_coding|badsyntax|site-packages' \
     "${FWK}/lib/python${PYVER}"
 
 "${FWK}/bin/python@PYVER@" -E -s -Wi \

Mac/Makefile.in

@@ -63,7 +63,6 @@ installunixtools:
 	fi
 	cd "$(DESTDIR)$(FRAMEWORKUNIXTOOLSPREFIX)/bin" && \
 	for fn in \
-			2to3 \
 			idle3 \
 			pydoc3 \
 			python3 \
@@ -123,7 +122,6 @@ altinstallunixtools:
 	fi
 	cd "$(DESTDIR)$(FRAMEWORKUNIXTOOLSPREFIX)/bin" && \
 	for fn in \
-			2to3-$(VERSION) \
 			idle$(VERSION) \
 			pydoc$(VERSION) \
 			python$(VERSION) \