Global ext auth e2e test flake

[sunjayBhatia]

Failed test error:

  [FAILED] 
  	Error Trace:	/home/runner/work/contour/contour/test/e2e/httpproxy/global_external_auth_test.go:197
  	            				/home/runner/go/pkg/mod/github.com/onsi/ginkgo/v2@v2.17.1/internal/node.go:472
  	            				/home/runner/go/pkg/mod/github.com/onsi/ginkgo/v2@v2.17.1/internal/suite.go:889
  	            				/opt/hostedtoolcache/go/1.22.1/x64/src/runtime/asm_amd64.s:1695
  	Error:      	Should be true
  	Test:       	HTTPProxy global external auth with namespace: httpproxy-global-ext-auth-tls with global external auth service global external auth can be configured on a TLS HTTPProxy
  	Messages:   	expected 401 response code, got 403
  
  In [It] at: /home/runner/work/contour/contour/test/e2e/httpproxy/global_external_auth_test.go:197 @ 04/07/24 20:33:53.48

See runs:

• https://github.com/projectcontour/contour/actions/runs/8591358101/job/23540070849?pr=6322