community/icingaweb2: remove optional dependencies
This MR removes the dependency on gd and imagick, which reduces the installed size of this aport (including dependencies) by about 100mb.
These php modules are only used when you run an pdf-export in icingaweb, a feature which is only rarely used in the wild (afaik).
If required, these modules can be installed manually afterwards without problems to provide the pdf-export feature.
List of dependencies which are removed:
(1/46) Purging php8-gd (8.0.13-r0)
(2/46) Purging php8-pecl-imagick (3.6.0-r0)
(3/46) Purging imagemagick (7.1.0.16-r0)
(4/46) Purging librsvg (2.50.7-r1)
(5/46) Purging pango (1.48.10-r0)
(6/46) Purging cairo-gobject (1.16.0-r3)
(7/46) Purging cairo (1.16.0-r3)
(8/46) Purging libxpm (3.5.13-r0)
(9/46) Purging imagemagick-libs (7.1.0.16-r0)
(10/46) Purging libxext (1.3.4-r0)
(11/46) Purging libxft (2.3.4-r0)
(12/46) Purging libxrender (0.9.10-r3)
(13/46) Purging libxt (1.2.1-r0)
(14/46) Purging libx11 (1.7.2-r0)
(15/46) Purging libxcb (1.14-r2)
(16/46) Purging libxau (1.0.9-r0)
(17/46) Purging libxdmcp (1.1.3-r0)
(18/46) Purging libsm (1.2.3-r0)
(19/46) Purging libice (1.0.10-r0)
(20/46) Purging ghostscript (9.55.0-r0)
(21/46) Purging harfbuzz (3.0.0-r2)
(22/46) Purging fontconfig (2.13.1-r4)
(23/46) Purging freetype (2.11.0-r0)
(24/46) Purging gdk-pixbuf (2.42.6-r0)
(25/46) Purging shared-mime-info (2.1-r0)
(26/46) Purging libpng (1.6.37-r1)
(27/46) Purging tiff (4.3.0-r0)
(28/46) Purging libjpeg-turbo (2.1.2-r0)
(29/46) Purging libwebp (1.2.1-r0)
(30/46) Purging lcms2 (2.12-r1)
(31/46) Purging libltdl (2.4.6-r7)
(32/46) Purging pixman (0.40.0-r3)
(33/46) Purging glib (2.70.1-r0)
(34/46) Purging libmount (2.37.2-r1)
(35/46) Purging cups-libs (2.3.3-r4)
(36/46) Purging avahi-libs (0.8-r5)
(37/46) Purging dbus-libs (1.12.20-r4)
(38/46) Purging jbig2dec (0.19-r0)
(39/46) Purging libheif (1.12.0-r2)
(40/46) Purging aom-libs (3.2.0-r0)
(41/46) Purging libde265 (1.0.8-r1)
(42/46) Purging x265-libs (3.5-r0)
(43/46) Purging pkgconf (1.8.0-r0)
(44/46) Purging fribidi (1.0.11-r0)
(45/46) Purging graphite2 (1.3.14-r0)
(46/46) Purging libgomp (10.3.1_git20211027-r0)