jetbrains: fix application icon (#239416)

My Desktop doesn't recognize the icon in ~/.local/share/pixmaps which is
how the icon would have to be found when doing a user profile install.

For me, it's hard to find information on this, but it seems like
share/pixmaps is something old and the share/icons location should be
used instead:

https://www.reddit.com/r/linuxquestions/comments/htg6c/comment/c1yfi0a/

https://github.com/spyder-ide/spyder/issues/6188

https://github.com/FreeSpacenav/spnavcfg/issues/9

In this PR we _add_ the icons location so that both are available for
compatibility.

pkgs/applications/editors/jetbrains/linux.nix

···
   installPhase = ''
     runHook preInstall
 
-    mkdir -p $out/{bin,$pname,share/pixmaps,libexec/${pname}}
+    mkdir -p $out/{bin,$pname,share/pixmaps,libexec/${pname},share/icons/hicolor/scalable/apps}
     cp -a . $out/$pname
     [[ -f $out/$pname/bin/${loName}.png ]] && ln -s $out/$pname/bin/${loName}.png $out/share/pixmaps/${pname}.png
-    [[ -f $out/$pname/bin/${loName}.svg ]] && ln -s $out/$pname/bin/${loName}.svg $out/share/pixmaps/${pname}.svg
+    [[ -f $out/$pname/bin/${loName}.svg ]] && ln -s $out/$pname/bin/${loName}.svg $out/share/pixmaps/${pname}.svg \
+      && ln -s $out/$pname/bin/${loName}.svg $out/share/icons/hicolor/scalable/apps/${pname}.svg
     mv bin/fsnotifier* $out/libexec/${pname}/.
 
     jdk=${jdk.home}