[systemd] turn MSAn on (#6514)

Apparently the dependencies aren't used at runtime by the
fuzz targets so it seems it should be safe to bring MSAn back.
I'd keep https://github.com/systemd/systemd/issues/20542 open though
(at least until the dependencies are either linked properly or
maybe even removed somehow).
diff --git a/projects/systemd/project.yaml b/projects/systemd/project.yaml
index 8c4bf79..c3eb6b2 100644
--- a/projects/systemd/project.yaml
+++ b/projects/systemd/project.yaml
@@ -5,8 +5,7 @@
 sanitizers:
   - address
   - undefined
-# Disabled MSAN because of https://github.com/google/oss-fuzz/issues/6294
-#  - memory
+  - memory
 auto_ccs:
   - jonathan@titanous.com
   - zbyszek@in.waw.pl
@@ -23,4 +22,4 @@
   - the.anitazha@gmail.com
   - daan.j.demeyer@gmail.com
   - luca.boccassi@gmail.com
-main_repo: 'https://github.com/systemd/systemd'
\ No newline at end of file
+main_repo: 'https://github.com/systemd/systemd'