refactor: Some proof clean up

HepLean/SpaceTime/LorentzVector/Modules.lean

@@ -55,7 +55,7 @@ lemma ext (ψ ψ' : ContrℂModule) (h : ψ.val = ψ'.val) : ψ = ψ' := by
   cases ψ
   cases ψ'
   subst h
-  simp_all only
+  rfl
 
 @[simp]
 lemma val_add (ψ ψ' : ContrℂModule) : (ψ + ψ').val = ψ.val + ψ'.val := rfl

HepLean/SpaceTime/MinkowskiMetric.lean

@@ -83,7 +83,6 @@ lemma off_diag_zero {μ ν : Fin 1 ⊕ Fin d} (h : μ ≠ ν) : η μ ν = 0 :=
   exact diagonal_apply_ne _ h
 
 lemma inl_0_inl_0 : @minkowskiMatrix d (Sum.inl 0) (Sum.inl 0) = 1 := by
-  simp only [minkowskiMatrix, LieAlgebra.Orthogonal.indefiniteDiagonal]
   rfl
 
 lemma inr_i_inr_i (i : Fin d) : @minkowskiMatrix d (Sum.inr i) (Sum.inr i) = -1 := by