[stdlib] Remove Intable from StaticTuple.__getitem__

As mentioned at
#2337 (comment), we've
pivoted a bit and moved away from `Intable` for offsets in `__getitem__`
implementations now that we have `Indexer`.  Fix this last use of `__getitem__`
that works on a `Intable` type to use `Int` explicitly.

MODULAR_ORIG_COMMIT_REV_ID: 87e2eca61466072aa0e36741296cb1d8fbc0eaed

stdlib/src/utils/static_tuple.mojo

@@ -193,25 +193,21 @@ struct StaticTuple[element_type: AnyTrivialRegType, size: Int](Sized):
         self = tmp
 
     @always_inline("nodebug")
-    fn __getitem__[intable: Intable](self, index: intable) -> Self.element_type:
+    fn __getitem__(self, idx: Int) -> Self.element_type:
         """Returns the value of the tuple at the given dynamic index.
 
-        Parameters:
-            intable: The intable type.
-
         Args:
-            index: The index into the tuple.
+            idx: The index into the tuple.
 
         Returns:
             The value at the specified position.
         """
-        var offset = int(index)
-        debug_assert(offset < size, "index must be within bounds")
+        debug_assert(idx < size, "index must be within bounds")
         # Copy the array so we can get its address, because we can't take the
         # address of 'self' in a non-mutating method.
         var arrayCopy = self.array
         var ptr = __mlir_op.`pop.array.gep`(
-            UnsafePointer.address_of(arrayCopy).address, offset.value
+            UnsafePointer.address_of(arrayCopy).address, idx.value
         )
         var result = Pointer(ptr)[]
         _ = arrayCopy

stdlib/test/utils/test_tuple.mojo

@@ -32,7 +32,6 @@ def test_static_tuple():
 
     assert_equal(tup3[0], 1)
     assert_equal(tup3[Int(0)], 1)
-    assert_equal(tup3[Int64(0)], 1)
 
 
 def test_static_int_tuple():