cmake/vcxproj: stop special-casing remote-ext

When the `vcxproj` target was introduced in `config.mak.uname` to allow
building Git with the Visual C toolchain, the `git remote-ext` command
was always executed in its dashed form. Therefore, it was impossible to
pass the test suite unless that command existed in its dashed form, and
we had to special-case this.

Later, when the `vcxproj` target got out of fashion because Visual
Studio gained native support for CMake builds, this special-casing was
copied without questioning it.

But as of 675df19 (transport-helper: do not run git-remote-ext etc.
in dashed form, 2020-08-26), the reason for this special-casing no
longer exists. So let's just drop it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

config.mak.uname

@@ -819,10 +819,6 @@ vcxproj:
 	sed -i 's|\(git\)-\([-a-z]*\)\.exe"|\1.exe" \2|g' \
 		bin-wrappers/git-{receive-pack,upload-archive}
 	git add -f $(test_bindir_programs)
-	# remote-ext is a builtin, but invoked as if it were external
-	sed 's|receive-pack|remote-ext|g' \
-		<bin-wrappers/git-receive-pack >bin-wrappers/git-remote-ext
-	git add -f bin-wrappers/git-remote-ext
 
 	# Add templates
 	$(MAKE) -C templates

contrib/buildsystems/CMakeLists.txt

@@ -1082,7 +1082,7 @@ endif()
 
 #wrapper scripts
 set(wrapper_scripts
-	git git-upload-pack git-receive-pack git-upload-archive git-shell git-remote-ext scalar)
+	git git-upload-pack git-receive-pack git-upload-archive git-shell scalar)
 
 set(wrapper_test_scripts
 	test-fake-ssh test-tool)