add date '2023' to cppreference bib entries

thesis/own.bib

@@ -91,6 +91,7 @@
     author = {cppreference.com},
     title = {{CPP Reference Entry on std::shared\_ptr<T>}},
     publisher = {cppreference},
+    date = {2023},
     url = {https://en.cppreference.com/w/cpp/memory/shared_ptr},
     urldate = {2024-01-17}
 }
@@ -99,6 +100,7 @@
     author = {cppreference.com},
     title = {{CPP Reference List of Atomic Operations}},
     publisher = {cppreference},
+    date = {2023},
     url = {https://en.cppreference.com/w/cpp/thread#Atomic_operations},
     urldate = {2024-01-18}
 }
@@ -107,6 +109,7 @@
     author = {cppreference.com},
     title = {{CPP Reference Entry on std::atomic<T>::wait}},
     publisher = {cppreference},
+    date = {2023},
     url = {https://en.cppreference.com/w/cpp/atomic/atomic/wait},
     urldate = {2024-01-18}
 }
@@ -115,6 +118,7 @@
     author = {cppreference.com},
     title = {{CPP Reference Entry on std::atomic<T>::notify\_one}},
     publisher = {cppreference},
+    date = {2023},
     url = {https://en.cppreference.com/w/cpp/atomic/atomic/notify_one},
     urldate = {2024-01-18}
 }
@@ -123,6 +127,7 @@
     author = {cppreference.com},
     title = {{CPP Reference Entry on std::atomic<T>::notify\_all}},
     publisher = {cppreference},
+    date = {2023},
     url = {https://en.cppreference.com/w/cpp/atomic/atomic/notify_all},
     urldate = {2024-01-18}
 }
@@ -131,6 +136,7 @@
     author = {cppreference.com},
     title = {{CPP Reference Entry on std::atomic<T>::exchange}},
     publisher = {cppreference},
+    date = {2023},
     url = {https://en.cppreference.com/w/cpp/atomic/atomic/exchange},
     urldate = {2024-01-18}
 }