[GTK] Remove duplicate device-zoom initialization in Image

[ptziegler]

The device zoom is hard-coded to 100% when creating blank images. Setting it to the current device zoom in the constructor is both wrong and unnecessary, given that the value will be immediately overwritten.

[ptziegler]

See

eclipse.platform.swt/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Image.java

Lines 1276 to 1278 in ebcb6b9

	// When we create a blank image we need to set it to 100 in GTK3 as we draw using 100% scale.
	// Cairo will take care of scaling for us when image needs to be scaled.
	currentDeviceZoom = 100;

[github-actions]

Test Results

   546 files  ±0     546 suites  ±0   26m 51s ⏱️ - 8m 7s
 4 412 tests ±0   4 395 ✅ ±0   17 💤 ±0  0 ❌ ±0 
16 718 runs  ±0  16 591 ✅ ±0  127 💤 ±0  0 ❌ ±0 

Results for commit fcae84c. ± Comparison against base commit ebcb6b9.

[akurtakov]

Good catch. Merging.