Browser tests: reduce timeout for instantiation to reasonable value

[HeikoKlare]

The timeout for browser instantiation in the browser tests has been increased to avoid flaky tests (via #1677). However, browser instantiation taking more than 10 seconds (the previous timeout value) is an indicator for something being wrong with the instantiation. There is no reason why instantiation may take that long during test execution but the same issue should never arise in productive use. Thus, such a case should be captured by tests and, if necessary, be fixed productively.

In order to do so, this change reduces the test timeout value again to a more reasonable value.

Related to #1676

Also see #1677 (comment)

[github-actions]

Test Results

   493 files   -  1     493 suites   - 1   10m 21s ⏱️ + 1m 15s
 4 289 tests  - 37   4 273 ✅  - 35   15 💤  - 3  1 ❌ +1 
16 500 runs   - 36  16 353 ✅  - 35  145 💤  - 3  2 ❌ +2 

For more details on these failures, see this check.

Results for commit 194a8a0. ± Comparison against base commit c493ae8.

This pull request removes 37 tests.

org.eclipse.swt.graphics.ImageWin32Tests ‑ testImageDataForDifferentFractionalZoomsShouldBeDifferent
org.eclipse.swt.graphics.ImageWin32Tests ‑ testImageShouldHaveDimesionAsPerZoomLevel
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testByteArrayTransfer
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testFileTransfer
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testHtmlTransfer
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testImageTransfer_fromCopiedImage
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testImageTransfer_fromImage
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testImageTransfer_fromImageData
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testImageTransfer_fromImageDataFromImage
org.eclipse.swt.tests.win32.Test_org_eclipse_swt_dnd_DND ‑ testRtfTransfer
…

♻️ This comment has been updated with latest results.

[HeikoKlare]

Builds sporadically show timeouts, e.g.:

Error:  Tests run: 380, Failures: 1, Errors: 0, Skipped: 12, Time elapsed: 193.3 s <<< FAILURE! -- in org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser
Error:  org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser.test_BrowserFunction_callback[browser flags: 0] -- Time elapsed: 66.79 s <<< FAILURE!
java.lang.AssertionError: creating browser took too long: 65267ms
	at org.junit.Assert.fail(Assert.java:89)
	at org.junit.Assert.assertTrue(Assert.java:42)
	at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser.createBrowser(Test_org_eclipse_swt_browser_Browser.java:312)
	at org.eclipse.swt.tests.junit.Test_org_eclipse_swt_browser_Browser.setUp(Test_org_eclipse_swt_browser_Browser.java:185)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)

Might be related to eclipse-platform/eclipse.platform.ui#2734