Add CXXFLAGS to jemalloc configuration for static build

rockylinux9/Dockerfile

@@ -561,7 +561,7 @@ RUN git clone --branch=1.3.15 --depth=1 https://github.com/sewenew/redis-plus-pl
 RUN git clone --branch=5.3.1 --depth=1 https://github.com/jemalloc/jemalloc.git src \
     && cd src \
     && ./autogen.sh \
-    && CFLAGS=-fPIC ./configure --prefix=/usr/local \
+    && CFLAGS=-fPIC CXXFLAGS=-fPIC ./configure --prefix=/usr/local \
         --disable-doc \
         --disable-shared \
         --enable-static \