Don't try to test files named with a trailing dot on Windows

The pg_verify_checksums test tries to create files with corrupt data
named "123." and "123_." But on Windows a file name with a trailing dot
is the same as a file without the trailing dot. In the first case this
will create a file with a "valid" name, which causes the test to fail in
an unexpected way, and in the secongd case this will be redandant as the
test already creates a file named "123_".

Bug discovered by buildfarm animal bowerbird.

src/bin/pg_verify_checksums/t/002_actions.pl

@@ -19,9 +19,11 @@ command_like(['pg_controldata', $pgdata],
 
 # Add set of dummy files with some contents.  These should not be scanned
 # by the tool.
-append_to_file "$pgdata/global/123.", "foo";
+
+# On Windows, file name "foo." == "foo", so skip that pattern there.
+append_to_file "$pgdata/global/123.", "foo" unless $windows_os;
 append_to_file "$pgdata/global/123_", "foo";
-append_to_file "$pgdata/global/123_.", "foo";
+append_to_file "$pgdata/global/123_.", "foo" unless $windows_os;;
 append_to_file "$pgdata/global/123.12t", "foo";
 append_to_file "$pgdata/global/foo", "foo2";
 append_to_file "$pgdata/global/t123", "bar";
@@ -32,7 +34,7 @@ append_to_file "$pgdata/global/_init", "foobar3";
 append_to_file "$pgdata/global/_vm.123", "foohoge";
 append_to_file "$pgdata/global/123_vm.123t", "foohoge2";
 
-# Those are correct but empty files, so they should pass through.
+# These are correct but empty files, so they should pass through.
 append_to_file "$pgdata/global/99999", "";
 append_to_file "$pgdata/global/99999.123", "";
 append_to_file "$pgdata/global/99999_fsm", "";