[Frontend] Support static_argnums (#476)

**Context:** Supporting ``static_argnums`` to identify which arguments
are static. I

**Description of the Change:** Introduce the ``static_argnums``
parameter to ``@qjit`` and add a mechanism to determine if the function
needs to be recompiled when the static arguments are changed.

**Benefits:** Users can pass custom objects to a function with
``@qjit``. The ``QJIT`` object also stores all previously compiled
functions for different arguments. If the arguments are seen before,
there is no need for re-compilation.

**Possible Drawbacks:** The ``QJIT`` object will store all the
previously compiled functions and require more space.
The mechanism for recompilation is based on checking hash values, so
there might be a possibility of collision. It also creates a new
``catalyst.utils.filesystem.WorkspaceManager`` for every new function.
If we do not create a new ``WorkspaceManager``, the new function will
not be properly compiled. I am not sure if I should modify anything
related to it.

**Related GitHub Issues:** closes #461

---------

Co-authored-by: Tzung-Han Juang <tzung-han.juang@mail.mcgill.ca>
Co-authored-by: David Ittah <dime10@users.noreply.github.com>

doc/changelog.md

@@ -2,6 +2,44 @@
 
 <h3>New features</h3>
 
+* Catalyst now supports just-in-time compilation of static arguments.
+  [(#476)](https://github.com/PennyLaneAI/catalyst/pull/476)
+
+  The ``@qjit`` decorator can now be used to compile functions with static arguments with
+  the ``static_argnums`` keyword argument. ``static_argnums`` can be an integer or an iterable
+  of integers that specify which positional arguments of a compiled function should be treated as
+  static. This feature allows users to pass hashable Python objects to a compiled function (as the
+  static arguments).
+
+  A ``qjit`` object stores the hash value of a compiled function's static arguments. If any static
+  arguments are changed, the ``qjit`` object will check its stored hash values. If no hash value is
+  found, the function will be re-compiled with new static arguments. Otherwise, no re-compilation
+  will be triggered and the previously compiled function will be used.
+
+  ```py
+  from dataclasses import dataclass
+
+  from catalyst import qjit
+
+  @dataclass
+  class MyClass:
+      val: int
+
+      def __hash__(self):
+          return hash(str(self))
+
+  @qjit(static_argnums=(1,))
+  def f(
+      x: int,
+      y: MyClass,
+  ):
+      return x + y.val
+
+  f(1, MyClass(5))
+  f(1, MyClass(6)) # re-compilation
+  f(2, MyClass(5)) # no re-compilation
+  ```
+
 <h3>Improvements</h3>
 
 * Add native support for `qml.PSWAP` and `qml.ISWAP` gates on Amazon Braket devices. Specifically, a circuit like
@@ -140,6 +178,7 @@ This release contains contributions from (in alphabetical order):
 Mikhail Andrenkov,
 Ali Asadi,
 David Ittah,
+Tzung-Han Juang,
 Erick Ochoa Lopez,
 Haochen Paul Wang.