Restrict nopre compat to OrdinaryDiffEqLowOrderRK/Tsit5 v2 only

Changing from "1.2.0, 2" to "2" forces the nopre sub-environment to
always resolve OrdinaryDiffEqLowOrderRK v2 and OrdinaryDiffEqTsit5 v2
(which require OrdinaryDiffEqCore v4 + SciMLBase v3).

This avoids the OrdinaryDiffEqCore v3.33.1 precompilation failure caused
by a bug where that version calls SciMLBase.derivative_discontinuity!
(only available in SciMLBase v3) while its compat specifies SciMLBase v2.
The nopre test environment switches sub-environments mid-session and
cannot mix SciMLBase v2 (main env) and the failing ODECore v3.33.1.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>

Author: ChrisRackauckas

test/nopre/Project.toml

@@ -19,8 +19,8 @@ ForwardDiff = "0.10.36"
 Functors = "0.5"
 JET = "0.9, 0.10, 0.11"
 JLArrays = "0.1, 0.2"
-OrdinaryDiffEqLowOrderRK = "1.2.0, 2"
-OrdinaryDiffEqTsit5 = "1.1.0, 2"
+OrdinaryDiffEqLowOrderRK = "2"
+OrdinaryDiffEqTsit5 = "2"
 QuadGK = "2.9"
 SciMLSensitivity = "7.105"
 Tracker = "0.2.35"