Fix Property Test

[maennchen]

https://github.com/erlef/mix_sbom/actions/runs/26445021908/job/77848991354?pr=113

Run mix coveralls.lcov \
Running ExUnit with seed: 594077, max_cases: 8
Excluding tags: [:test]
Including tags: [:property]

.

  1) property XML round-trip preserves BOM structure (SBoM.CycloneDXTest)
Error:      test/sbom/cyclonedx_test.exs:68
     ** (exit) {:fatal, {{:error, {:wfc_Legal_Character, 11}}, {:file, :file_name_unknown}, {:line, 1}, {:col, 4191}}}
     code: check all(
     stacktrace:
       (xmerl 2.1.9) xmerl_scan.erl:4237: :xmerl_scan.fatal/2
       (xmerl 2.1.9) xmerl_scan.erl:2829: :xmerl_scan.scan_char_data/5
       (xmerl 2.1.9) xmerl_scan.erl:2741: :xmerl_scan.scan_content/11
       (xmerl 2.1.9) xmerl_scan.erl:2244: :xmerl_scan.scan_element/12
       (xmerl 2.1.9) xmerl_scan.erl:2716: :xmerl_scan.scan_content/11
       (xmerl 2.1.9) xmerl_scan.erl:2244: :xmerl_scan.scan_element/12
       (xmerl 2.1.9) xmerl_scan.erl:2716: :xmerl_scan.scan_content/11
       (xmerl 2.1.9) xmerl_scan.erl:2244: :xmerl_scan.scan_element/12
       (xmerl 2.1.9) xmerl_scan.erl:2716: :xmerl_scan.scan_content/11
       (xmerl 2.1.9) xmerl_scan.erl:2244: :xmerl_scan.scan_element/12
       (xmerl 2.1.9) xmerl_scan.erl:678: :xmerl_scan.scan_document/2
       (xmerl 2.1.9) xmerl_scan.erl:392: :xmerl_scan.string/2
       (sbom 0.10.0) lib/sbom/cyclonedx/xml.ex:39: SBoM.CycloneDX.XML.decode/1
       test/sbom/cyclonedx_test.exs:87: anonymous fn/3 in SBoM.CycloneDXTest."property XML round-trip preserves BOM structure"/1
       (stream_data 1.3.0) lib/stream_data.ex:2510: StreamData.check_all/7
       test/sbom/cyclonedx_test.exs:69: (test)

     The following output was logged:
     
Error:      09:48:59.936 [error] 3540- fatal: {:error, {:wfc_Legal_Character, 11}}