Update CODEOWNERS (#32716)

.github/CODEOWNERS

@@ -2,3 +2,15 @@
 # Protection of the spell-check rules makes no sense as it needs to be changed in nearly every PR.
 /.github/ @crutkas @DHowett @ethanfangg
 /.github/actions/spell-check/
+
+# locking down pipeline folder
+/.pipelines @crutkas @DHowett @ethanfangg
+
+# locking down nuget config
+nuget.config  @crutkas @DHowett @ethanfangg
+packages.config  @crutkas @DHowett @ethanfangg
+
+# locking down files that should not change
+LICENSE @crutkas @DHowett @ethanfangg
+SECURITY.MD @crutkas @DHowett @ethanfangg
+CODE_OF_CONDUCT.MD @crutkas @DHowett @ethanfangg