TEST - Fixture changes to find the issue on FF

[stockiNail]

Created only to test why the fixture test cases are failing with FF (and only with FF).

[stockiNail]

See job https://github.com/chartjs/chartjs-plugin-annotation/actions/runs/4270427856/jobs/7434218854

[karma] Firefox 110.0 (Ubuntu 0.0.0) Point annotation auto /base/test/fixtures/point/boxLocation.js FAILED
[karma] 	Fixture test failed:
[karma] 	  Difference: 1572px / 0.6%
[karma] 	  Threshold: 10%
[karma] 	  Tolerance: 0.1%
[karma] 	<Jasmine>
[karma] 	specFromFixture/</</_done/<@node_modules/chartjs-test-utils/dist/chartjs-test-utils.js:1086:25 <- test/index.js:901:27
[karma] 	readImageData/image.onload@node_modules/chartjs-test-utils/dist/chartjs-test-utils.js:527:13 <- test/index.js:364:15
[karma] Chrome 110.0.0.0 (Linux x86_64): Executed 181 of 372 SUCCESS (0 secs / 8.473 secs)
[karma] Firefox 110.0 (Ubuntu 0.0.0): Executed 25 of 372 (1 FAILED) (0 secs / 1.737 secs)
[karma] Firefox 110.0 (Ubuntu 0.0.0) Point annotation auto /base/test/fixtures/point/boxLocation.js FAILED
[karma] 	Fixture test failed:
[karma] 	  Difference: 1572px / 0.6%
[karma] 	  Threshold: 10%
[karma] 	  Tolerance: 0.1%
[karma] 	<Jasmine>
[karma] 	specFromFixture/</</_done/<@node_modules/chartjs-test-utils/dist/chartjs-test-utils.js:1086:25 <- test/index.js:901:27
[karma] 	readImageData/image.onload@node_modules/chartjs-test-utils/dist/chartjs-test-utils.js:527:13 <- test/index.js:364:15
[karma] Firefox 110.0 (Ubuntu 0.0.0) Point annotation auto /base/test/fixtures/point/boxLocation.js FAILED
[karma] 	Fixture test failed:
[karma] 	  Difference: 1572px / 0.6%
[karma] 	  Threshold: 10%
[karma] 	  Tolerance: 0.1%
[karma] 	<Jasmine>
[karma] 	specFromFixture/</</_done/<@node_modules/chartjs-test-utils/dist/chartjs-test-utils.js:1086:25 <- test/index.js:901:27
[karma] 	readImageData/image.onload@node_modules/chartjs-test-utils/dist/chartjs-test-utils.js:527:13 <- test/index.js:364:15

I have creeatd the fixture "point/boxLocation" locally (and it works) and added to this PR, by FF 110.

[stockiNail]

The last NODE Ci ended correctly was the following: https://github.com/chartjs/chartjs-plugin-annotation/actions/runs/4164571764/jobs/7206378938
It was the last with FF 109. After this CI, the next one failed (https://github.com/chartjs/chartjs-plugin-annotation/actions/runs/4264451113/jobs/7422543727) using FF 110.....

[stockiNail]

@kurkle @LeeLenaleee having a look to this issue about tests on fixtures, I had a look to Chart,js as well, because I didnt understand how this could work in Chart.js and why not here.

If you have a look to Chart.js CI https://github.com/chartjs/Chart.js/actions/workflows/ci.yml, you can see that last test ended correctly was https://github.com/chartjs/Chart.js/actions/runs/4184874762/jobs/7251128906 where FF 109 was used.

The last ones, failed like in this plugin, with FF 110.