remove outdated handling of :static_parameter

After #51970, `Expr(:static_parameter, i::Int)` is now consistently
outlined during the lowering, so there's no longer a need for
`abstract_eval_value_expr` to handle this expression. This update
removes the outdated handling, clarifying where we need to handle
the expression.

Author: aviatesk

base/compiler/abstractinterpretation.jl

@@ -2340,20 +2340,7 @@ function abstract_eval_special_value(interp::AbstractInterpreter, @nospecialize(
 end
 
 function abstract_eval_value_expr(interp::AbstractInterpreter, e::Expr, vtypes::Union{VarTable,Nothing}, sv::AbsIntState)
-    head = e.head
-    if head === :static_parameter
-        n = e.args[1]::Int
-        nothrow = false
-        if 1 <= n <= length(sv.sptypes)
-            sp = sv.sptypes[n]
-            rt = sp.typ
-            nothrow = !sp.undef
-        else
-            rt = Any
-        end
-        merge_effects!(interp, sv, Effects(EFFECTS_TOTAL; nothrow))
-        return rt
-    elseif head === :call
+    if e.head === :call
         # TODO: We still have non-linearized cglobal
         @assert e.args[1] === Core.tuple ||
                 e.args[1] === GlobalRef(Core, :tuple)