[GTK] Set useCairoAutoScale to true and remove getter

[akurtakov]

Change all implementations to not check it but act assume it is always true. This was the case anyway as Device.init explicitly set it that way.

[github-actions]

Test Results

   431 files  +   431     431 suites  +431   17m 55s ⏱️ + 17m 55s
 4 144 tests + 4 144   4 127 ✅ + 4 127   9 💤 + 9  8 ❌ +8 
12 361 runs  +12 361  12 302 ✅ +12 302  51 💤 +51  8 ❌ +8 

For more details on these failures, see this check.

Results for commit bfe6f51. ± Comparison against base commit 9e57eae.

♻️ This comment has been updated with latest results.

[akurtakov]

Build breaks due to https://gitlab.eclipse.org/eclipsefdn/helpdesk/-/issues/5893

[akurtakov]

Failing windows tests are unrelated to gtk change. Merging.

[HeikoKlare]

Failing windows tests are unrelated to gtk change. Merging.

@akurtakov are you sure? I think this actually introduced the Windows test failures. See also #2031 (comment)

I will propose a fix.

[akurtakov]

@HeikoKlare Sorry my fault! Instability of infrastructure and tests lately made me sloppy.

[HeikoKlare]

No worries, fix seems easy :-)

• Correct Cairo autoscaling setting in DPIUtil and remove setter #2031 #2032