Fix additional SyntaxWarnings with Python 3.12

It seems that Python 3.12 has started emitting additional SyntaxWarnings
in cases where there are backslashes used in strings, so change these
strings to raw strings to avoid the warnings.

wx/lib/docview.py

@@ -1023,7 +1023,7 @@ class DocTemplate(wx.Object):
 
 
     def __init__(self, manager, description, filter, dir, ext, docTypeName, viewTypeName, docType, viewType, flags=DEFAULT_TEMPLATE_FLAGS, icon=None):
-        """
+        r"""
         Constructor. Create instances dynamically near the start of your
         application after creating a wxDocManager instance, and before doing
         any document or view operations.

wx/lib/layoutf.py

@@ -132,8 +132,8 @@ class Layoutf(wx.LayoutConstraints):
              'r': 'wx.Right', 'h': 'wx.Height', 'w': 'wx.Width',
              'x': 'wx.CentreX', 'y': 'wx.CentreY' }
 
-    rexp1 = re.compile('^\s*([tlrbhwxy])\s*([!\?\*])\s*(\d*)\s*$')
-    rexp2 = re.compile('^\s*([tlrbhwxy])\s*([=%<>^_])\s*([tlrbhwxy]?)\s*(\d*)\s*#(\d+)\s*$')
+    rexp1 = re.compile(r'^\s*([tlrbhwxy])\s*([!\?\*])\s*(\d*)\s*$')
+    rexp2 = re.compile(r'^\s*([tlrbhwxy])\s*([=%<>^_])\s*([tlrbhwxy]?)\s*(\d*)\s*#(\d+)\s*$')
 
     def __init__(self,pstr=None,winlist=None):
         wx.LayoutConstraints.__init__(self)

wx/lib/wxpTag.py

@@ -14,7 +14,7 @@
 # o Updated for V2.5 compatibility
 #
 
-'''
+r'''
 wx.lib.wxpTag
 
 This module contains a wxHtmlTagHandler that knows how to build

wx/tools/pywxrc.py

@@ -521,7 +521,7 @@ class XmlResourceCompiler:
         # Generate subclasses
         for subclass in subclasses:
             windowClass = bases[subclass]
-            subclass = re.sub("^\S+\.", "", subclass)
+            subclass = re.sub(r"^\S+\.", "", subclass)
             windowClass = re.sub("^wx", "", windowClass)
             outputList.append(self.templates.SUBCLASS_HEADER % locals())
             outputList.append('\n')
@@ -760,7 +760,7 @@ class XmlResourceCompiler:
     #-------------------------------------------------------------------
 
     def ConvertText(self, st):
-        """
+        r"""
         Encode special characters as escaped C/Python string characters.
 
             \n => \\n