Remove qmake build files

Removes qmake as a build system for building Qt Creator itself.
Keep them for some tests that are not completely moved to CMake yet.

Change-Id: I846c6ef65626b6dfae6375fdc85d00677aa8c2fb
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/docker/docker.pro

@@ -1,17 +0,0 @@
-include(../../qtcreatorplugin.pri)
-
-DEFINES += QT_RESTRICTED_CAST_FROM_ASCII
-
-SOURCES += \
-    dockerbuildstep.cpp \
-    dockerdevice.cpp \
-    dockerplugin.cpp \
-    dockersettings.cpp
-
-HEADERS += \
-    docker_global.h \
-    dockerbuildstep.h \
-    dockerconstants.h \
-    dockerdevice.h \
-    dockerplugin.h \
-    dockersettings.h

src/plugins/docker/docker_dependencies.pri

@@ -1,7 +0,0 @@
-QTC_PLUGIN_NAME = Docker
-QTC_LIB_DEPENDS += \
-    utils
-QTC_PLUGIN_DEPENDS += \
-    coreplugin \
-    projectexplorer \
-    qtsupport