🩹 Fix default expected constructors

When `= default`ing constructors, it can be detrimental to specify
the `noexcept`-ness and `constexpr`-ness of the constructor since it
may either be misleading, or worse, implicitly deleted if the
`noexcept`ness cannot be satisfied.

GCC has determined that `expected() noexcept = default` is resulting in
an implicitly deleted default-constructor due to the constructor not
actually being `noexcept`. The exact reason for this failure is not
known, but realistically, the non-throwing nature of the constructor
should *not* be cause for this type of issue.

As a result, all `expected` constructors have removed `constexpr` or
implicitly expected `noexcept`-ness to instead simply be determined
by the compiler with `= default`.

lib/alloy-core/include/alloy/core/utilities/expected.hpp

@@ -294,7 +294,7 @@ namespace alloy::core {
 
     /// \brief Constructs the underlying value by default-construction by
     ///        calling T's constructor
-    constexpr expected() = default;
+    expected() = default;
 
     /// \brief Constructs the underlying value of this expected by calling
     ///        T's constructor with the given args
@@ -334,12 +334,12 @@ namespace alloy::core {
     /// \brief Constructs this expected by moving the contents of \p other
     ///
     /// \param other the other expected to move
-    constexpr expected(expected&& other) = default;
+    expected(expected&& other) = default;
 
     /// \brief Constructs this expected by copying the contents of \p other
     ///
     /// \param other the other expected to copy
-    constexpr expected(const expected& other) = default;
+    expected(const expected& other) = default;
 
     //--------------------------------------------------------------------------
 
@@ -516,7 +516,7 @@ namespace alloy::core {
   public:
 
     /// \brief Constructs this expected successfully
-    constexpr expected() noexcept = default;
+    expected() = default;
 
     /// \brief Constructs the underlying error of this expected
     ///
@@ -528,12 +528,12 @@ namespace alloy::core {
     /// \brief Constructs this expected by moving the contents of \p other
     ///
     /// \param other the other expected to move
-    constexpr expected(expected&& other) = default;
+    expected(expected&& other) = default;
 
     /// \brief Constructs this expected by copying the contents of \p other
     ///
     /// \param other the other expected to copy
-    constexpr expected(const expected& other) = default;
+    expected(const expected& other) = default;
 
     //--------------------------------------------------------------------------