CI: do not try to install original posterdown

seems to be removed from CRAN

Change-Id: I9ea7ff532cf2b4757815008a34cd73b45d084512
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f22ff65..92ed28b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -48,7 +48,7 @@
 #    - echo -e 'local({r <- getOption("repos")\n r["CRAN"] <- "https://cloud.r-project.org"\n options(repos=r)})' > ~/.Rprofile
     - echo "options(Ncpus=$(nproc))" >> ~/.Rprofile
     - R -e "install.packages('pak', dependencies=TRUE)"
-    - R -e "pak::pak(c('devtools', 'scales', 'sp', 'raster', 'kableExtra', 'DT', 'svglite', 'qrcode', 'posterdown'))"
+    - R -e "pak::pak(c('devtools', 'scales', 'sp', 'raster', 'kableExtra', 'DT', 'svglite', 'qrcode', 'ggthemes', 'patchwork', 'pagedown'), dependencies=TRUE)"
     - R -e 'devtools::install_git("https://korap.ids-mannheim.de/gerrit/IDS-Mannheim/idsThemeR", dependencies=TRUE)'
     - R -e 'devtools::install_git("https://korap.ids-mannheim.de/gerrit/IDS-Mannheim/posterdown", dependencies=TRUE)'
     - end_section install_r_packages