setup: use the full executable manifest from `python.exe`

The manifest embedded by the build process (before the string here is added)
already accounts for the `<requestedExecutionLevel level="asInvoker" ...>`
setting.  (Note that the PyOxidizer build is missing this, so it will likely
trigger the UAC escalation prompt on each run.)  However, using `mt.exe` to
merge the fragment with what is already in the manifest seems to strip all
whitespace, making it unreadable.

Since Mercurial can be run via `python.exe`, it makes sense that we would have
the same manifest settings (like the supported OS list), though I'm unaware of
any functionality this enables.  It also has the nice effect of making the
content readable from a resource editor.  The manifest comes from python 3.9.12.

Note that this seems to strip the `<?xml ... ?>` declaration when viewed with
ResourceHacker 5.1.7, but this was also the state of things with the previous
commit, and `mt.exe "-inputresource:hg.exe;#1" -out:extracted` does contain the
declaration and the BOM in both cases.  No idea why this differs from other
executables.

setup.py

@@ -667,16 +667,51 b' class buildhgextindex(Command):'
 class buildhgexe(build_ext):
     description = 'compile hg.exe from mercurial/exewrapper.c'
 
-    LONG_PATHS_MANIFEST = """
-    <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-    <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
-        <application>
-            <windowsSettings
-            xmlns:ws2="http://schemas.microsoft.com/SMI/2016/WindowsSettings">
-                <ws2:longPathAware>true</ws2:longPathAware>
-            </windowsSettings>
-        </application>
-    </assembly>"""
+    LONG_PATHS_MANIFEST = """\
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges>
+        <requestedExecutionLevel
+          level="asInvoker"
+          uiAccess="false"
+        />
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- Windows Vista -->
+      <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
+      <!-- Windows 7 -->
+      <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
+      <!-- Windows 8 -->
+      <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
+      <!-- Windows 8.1 -->
+      <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
+      <!-- Windows 10 and Windows 11 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
+    </application>
+  </compatibility>
+  <application xmlns="urn:schemas-microsoft-com:asm.v3">
+    <windowsSettings
+        xmlns:ws2="http://schemas.microsoft.com/SMI/2016/WindowsSettings">
+      <ws2:longPathAware>true</ws2:longPathAware>
+    </windowsSettings>
+  </application>
+  <dependency>
+    <dependentAssembly>
+      <assemblyIdentity type="win32"
+                        name="Microsoft.Windows.Common-Controls"
+                        version="6.0.0.0"
+                        processorArchitecture="*"
+                        publicKeyToken="6595b64144ccf1df"
+                        language="*" />
+    </dependentAssembly>
+  </dependency>
+</assembly>
+"""
 
     def initialize_options(self):
         build_ext.initialize_options(self)
@@ -776,21 +811,18 b' class buildhgexe(build_ext):'
         exefname = self.compiler.executable_filename(self.hgtarget)
         fdauto, manfname = tempfile.mkstemp(suffix='.hg.exe.manifest')
         os.close(fdauto)
-        with open(manfname, 'w') as f:
+        with open(manfname, 'w', encoding="UTF-8") as f:
             f.write(self.LONG_PATHS_MANIFEST)
         log.info("long paths manifest is written to '%s'" % manfname)
-        inputresource = '-inputresource:%s;#1' % exefname
         outputresource = '-outputresource:%s;#1' % exefname
         log.info("running mt.exe to update hg.exe's manifest in-place")
-        # supplying both -manifest and -inputresource to mt.exe makes
-        # it merge the embedded and supplied manifests in the -outputresource
+
         self.spawn(
             [
                 self.compiler.mt,
                 '-nologo',
                 '-manifest',
                 manfname,
-                inputresource,
                 outputresource,
             ]
         )