make checkbounds(string, ...) return nothing or error

fix #24840 all the way, already mostly fixed by #24999

Author: StefanKarpinski

base/strings/basic.jl

@@ -178,7 +178,7 @@ checkbounds(::Type{Bool}, s::AbstractString, I::AbstractArray{<:Real}) =
 checkbounds(::Type{Bool}, s::AbstractString, I::AbstractArray{<:Integer}) =
     all(i -> checkbounds(s, i), I)
 checkbounds(s::AbstractString, I::Union{Integer,AbstractArray}) =
-    checkbounds(Bool, s, I) || throw(BoundsError(s, I))
+    checkbounds(Bool, s, I) ? nothing : throw(BoundsError(s, I))
 
 ## construction, conversion, promotion ##