flaky rebinding test, seems like invalidation sometimes doesn't happen after deleting a binding

[nsajko]

From CI of #56885

rebinding                                        (8) |        started at 2025-01-09T09:21:26.376
rebinding                                        (8) |         failed at 2025-01-09T09:21:26.848
Test Failed at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-XG3Q6T6R70.0/build/default-honeycrisp-XG3Q6T6R70-0/julialang/julia-master/julia-e11dfdce75/share/julia/test/rebinding.jl:42
  Expression: f_return_delete_me()
    Expected: UndefVarError
  No exception thrown
[...]
The global RNG seed was 0x65ab24200a3089a07dcec2ec2de11061.
Error in testset rebinding:
Test Failed at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-XG3Q6T6R70.0/build/default-honeycrisp-XG3Q6T6R70-0/julialang/julia-master/julia-e11dfdce75/share/julia/test/rebinding.jl:42
  Expression: f_return_delete_me()
    Expected: UndefVarError
  No exception thrown
ERROR: LoadError: Test run finished with errors
in expression starting at /Users/julia/.julia/scratchspaces/a66863c6-20e8-4ff4-8a62-49f30b1f605e/agent-cache/default-honeycrisp-XG3Q6T6R70.0/build/default-honeycrisp-XG3Q6T6R70-0/julialang/julia-master/julia-e11dfdce75/share/julia/test/runtests.jl:89
ERROR: A test has failed. Please submit a bug report (https://github.com/JuliaLang/julia/issues)
including error messages above and the output of versioninfo():
Julia Version 1.12.0-DEV.1867
Commit e11dfdce75f (2025-01-09 16:48 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: macOS (arm64-apple-darwin24.0.0)
  CPU: 8 × Apple M2
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, apple-m2)
  GC: Built with stock GC
Threads: 1 default, 0 interactive, 1 GC (on 4 virtual cores)
Environment:
  JULIA_INSTALL_DIR = julia-e11dfdce75
  JULIA_SHELL = /bin/bash
  JULIA_CPU_TARGET = generic;apple-m1,clone_all
  JULIA_TEST_MAXRSS_MB = 3800
  JULIA_CMD_FOR_TESTS = julia-e11dfdce75/bin/julia .buildkite/utilities/timeout.jl julia-e11dfdce75/bin/julia
  JULIA_TEST_VERBOSE_LOGS_DIR = /private/var/tmp/agent-tempdirs/default-honeycrisp-XG3Q6T6R70.0/tmp/jl_HcIskD
  JULIA_IMAGE_THREADS = 4
  JULIA_BINARYDIST_FILENAME = julia-e11dfdce75-macaarch64
  JULIA_CPU_THREADS = 4
  JULIA_NUM_THREADS = 1
  JULIA_VERSION = 1.12.0-DEV
  JULIA_TEST_IS_BASE_CI = true

https://buildkite.com/julialang/julia-master/builds/43630#01944bf8-a7ca-43ef-bd9f-9dc836a794cf/846-1149

The test:

julia/test/rebinding.jl

Lines 37 to 42 in 3d85309

	# Test invalidation (const -> undefined)
	const delete_me = 1
	f_return_delete_me() = delete_me
	@test f_return_delete_me() == 1
	Base.delete_binding(@__MODULE__, :delete_me)
	@test_throws UndefVarError f_return_delete_me()

cc @Keno

[Keno]

I fixed some bugs in this code in #57009, so this might be fixed soon. That PR also includes better error printing so if it's not fixed, it'll at least print better.