patch 9.0.0305: CI lists useless deprecation warnings

Problem:    CI lists useless deprecation warnings.
Solution:   Ignore deprecation warnings. (closes #11003)
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1e20067..ebbccd7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,7 +21,7 @@
       TEST: test
       SRCDIR: ./src
       LEAK_CFLAGS: -DEXITFREE
-      CFLAGS: -Wno-error=deprecated-declarations
+      CFLAGS: -Wno-deprecated-declarations
       LOG_DIR: ${{ github.workspace }}/logs
       TERM: xterm
       DISPLAY: ':99'