xrootd: update patch (#36350)

Due to case change, a patch in xrootd doesn't apply cleanly. This fixes the patch by turning it into a `filter_file` with a more limited regex match.

var/spack/repos/builtin/packages/xrootd/no-systemd.patch

@@ -1,17 +0,0 @@
---- a/cmake/XRootDFindLibs.cmake	2021-07-29 12:22:48.000000000 +0000
-+++ b/cmake/XRootDFindLibs.cmake	2021-10-25 18:26:07.308918231 +0000
-@@ -26,10 +26,10 @@
-   add_definitions( -DHAVE_XML2 )
- endif()
- 
--find_package( Systemd )
--if( SYSTEMD_FOUND )
--  add_definitions( -DHAVE_SYSTEMD )
--endif()
-+#find_package( Systemd )
-+#if( SYSTEMD_FOUND )
-+#  add_definitions( -DHAVE_SYSTEMD )
-+#endif()
- 
- find_package( CURL )
- 

var/spack/repos/builtin/packages/xrootd/package.py

@@ -15,6 +15,8 @@ class Xrootd(CMakePackage):
     url = "https://xrootd.slac.stanford.edu/download/v5.5.1/xrootd-5.5.1.tar.gz"
     list_url = "https://xrootd.slac.stanford.edu/dload.html"
 
+    maintainers("wdconinc")
+
     version("5.5.3", sha256="703829c2460204bd3c7ba8eaa23911c3c9a310f6d436211ba0af487ef7f6a980")
     version("5.5.2", sha256="ec4e0490b8ee6a3254a4ea4449342aa364bc95b78dc9a8669151be30353863c6")
     version("5.5.1", sha256="3556d5afcae20ed9a12c89229d515492f6c6f94f829a3d537f5880fcd2fa77e4")
@@ -91,11 +93,13 @@ class Xrootd(CMakePackage):
         when="@5.5.1",
     )
 
-    # do not use systemd
-    patch("no-systemd.patch")
-
     def patch(self):
-        """Remove hardcoded -std=c++0x flag"""
+        # Do not use systemd
+        filter_file(
+            r"(add_definitions\(\s*-DHAVE_SYSTEMD\s*\))", r"#\1", "cmake/XRootDFindLibs.cmake"
+        )
+
+        # Remove hardcoded -std=c++0x flag
         if self.spec.satisfies("@4.7.0:"):
             filter_file(r"\-std=c\+\+0x", r"", "cmake/XRootDOSDefs.cmake")