CI/GitHub: Switch to GCC 8 (#25610)

* CI/GitHub: Switch to GCC 8

Build on GitHub Actions using GCC 8 as it's the oldest supported GCC

* Core/Misc: Attempt to fix GCC 8 build

.github/workflows/gcc-build.yml

@@ -12,6 +12,7 @@ jobs:
     - name: Dependencies
       run: |
         sudo apt-get update && sudo apt-get install -yq libboost-all-dev
+        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 100 --slave /usr/bin/g++ g++ /usr/bin/g++-8
     - name: Setup
       run: |
         mkdir bin

src/server/game/Chat/ChatCommands/ChatCommandTags.h

@@ -108,7 +108,7 @@ namespace Trinity::ChatCommands
         private:
             static constexpr std::array<char, sizeof...(chars)> _storage = { chars... };
             static_assert(!_storage.empty() && (_storage.back() == '\0'), "ExactSequence parameters must be null terminated! Use the EXACT_SEQUENCE macro to make this easier!");
-            static constexpr std::string_view _string = { _storage.data() };
+            static constexpr std::string_view _string = { _storage.data(), std::string_view::traits_type::length(_storage.data()) };
     };
 
 #define EXACT_SEQUENCE(str) Trinity::ChatCommands::ExactSequence<CHATCOMMANDS_IMPL_SPLIT_LITERAL(str)>