[tests] Remove unused file. (#15936)

The mini tests were removed [eons][1] ago, so remove the remaining file as well.

[1]: c4a89496fc

tests/mini/Info.plist

@@ -1,28 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-	<key>CFBundleIdentifier</key>
-	<string>com.xamarin.mini</string>
-	<key>MinimumOSVersion</key>
-	<string>7.0</string>
-	<key>UIDeviceFamily</key>
-	<array>
-		<integer>1</integer>
-		<integer>2</integer>
-	</array>
-	<key>UISupportedInterfaceOrientations</key>
-	<array>
-		<string>UIInterfaceOrientationPortrait</string>
-		<string>UIInterfaceOrientationLandscapeLeft</string>
-		<string>UIInterfaceOrientationLandscapeRight</string>
-	</array>
-	<key>UISupportedInterfaceOrientations~ipad</key>
-	<array>
-		<string>UIInterfaceOrientationPortrait</string>
-		<string>UIInterfaceOrientationPortraitUpsideDown</string>
-		<string>UIInterfaceOrientationLandscapeLeft</string>
-		<string>UIInterfaceOrientationLandscapeRight</string>
-	</array>
-</dict>
-</plist>