flaky condition number-related tests in `test/linalg_solvers.jl`

[nsajko]

Flaky tests here:

SparseArrays.jl/test/linalg_solvers.jl

Lines 130 to 146 in 6fe51f2

	@testset "sparse matrix cond" begin
	local A = sparse(reshape([1.0], 1, 1))
	Ac = sprandn(20, 20,.5) + im*sprandn(20, 20,.5)
	Ar = sprandn(20, 20,.5) + eps()*I
	@test cond(A, 1) == 1.0
	# For a discussion of the tolerance, see #14778
	@test 0.99 <= cond(Ar, 1) \ opnorm(Ar, 1) * opnorm(inv(Array(Ar)), 1) < 3
	@test 0.99 <= cond(Ac, 1) \ opnorm(Ac, 1) * opnorm(inv(Array(Ac)), 1) < 3
	@test 0.99 <= cond(Ar, Inf) \ opnorm(Ar, Inf) * opnorm(inv(Array(Ar)), Inf) < 3
	@test 0.99 <= cond(Ac, Inf) \ opnorm(Ac, Inf) * opnorm(inv(Array(Ac)), Inf) < 3
	@test_throws ArgumentError cond(A,2)
	@test_throws ArgumentError cond(A,3)
	Arect = spzeros(10, 6)
	@test_throws DimensionMismatch cond(Arect, 1)
	@test_throws ArgumentError cond(Arect,2)
	@test_throws DimensionMismatch cond(Arect, Inf)
	end

Added in PR JuliaLang/julia#15113 to fix issue JuliaLang/LinearAlgebra.jl#301.

The test at line 136 above failed now in my PR JuliaLang/julia#59465.

CI link:

• https://buildkite.com/julialang/julia-master/builds/50280/steps/canvas?sid=01990b03-a25f-4803-9640-5a3f88078ed1#01990b03-a2a3-48f5-b107-374886d93dcf/911-1304

CI log excerpt:

SparseArrays/linalg_solvers                     (10) |         failed at 2025-09-02T09:02:29.135
Test Failed at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-HL2F7YQ3XH.0/build/default-honeycrisp-HL2F7YQ3XH-0/julialang/julia-master/julia-1d21dd31ac/share/julia/stdlib/v1.13/SparseArrays/test/linalg_solvers.jl:136
  Expression: 0.99 <= (cond(Ar, 1) \ opnorm(Ar, 1)) * opnorm(inv(Array(Ar)), 1) < 3
   Evaluated: 0.99 <= 3.02356520291477 < 3