No unused param warnings for clang-12 and gcc-11.

These have too many false positives in -Werror tests on the github CI
since we often provide empty stub functions for functionality not needed
for particular configurations.

.github/configs

@@ -38,13 +38,13 @@ case "$config" in
 	CC="clang-12"
 	# clang's implicit-fallthrough requires that the code be annotated with
 	# __attribute__((fallthrough)) and does not understand /* FALLTHROUGH */
-	CFLAGS="-Wall -Wextra -O2 -Wno-error=implicit-fallthrough"
+	CFLAGS="-Wall -Wextra -O2 -Wno-error=implicit-fallthrough -Wno-error=unused-parameter"
 	CONFIGFLAGS="--with-pam --with-Werror"
 	;;
     gcc-11-Werror)
 	CC="gcc"
 	# -Wnoformat-truncation in gcc 7.3.1 20180130 fails on fmt_scaled
-	CFLAGS="-Wall -Wextra -Wno-format-truncation -O2 -Wimplicit-fallthrough=4"
+	CFLAGS="-Wall -Wextra -O2 -Wno-format-truncation -Wimplicit-fallthrough=4 -Wno-unused-parameter"
 	CONFIGFLAGS="--with-pam --with-Werror"
 	;;
     clang*|gcc*)