Ease writeShellApplication calls

Provide proper runtimeInputs instead of using nix variables all the
time.

home/packages/custom/backup/default.nix

@@ -8,8 +8,14 @@
 writeShellApplication {
   name = "custom-backup";
 
+  runtimeInputs = [
+    borgbackup
+    rsync
+    git
+  ];
+
   text = ''
-    ${borgbackup}/bin/borg create \
+    borg create \
       -v \
       --progress \
       --stats \
@@ -17,11 +23,11 @@ writeShellApplication {
       /media/daniels/Backup/borg::"$(date +%F-%R)" \
       ~/
 
-    ${rsync}/bin/rsync -az ~/.config/nixpkgs /media/daniels/Backup/
+    rsync -az ~/.config/nixpkgs /media/daniels/Backup/
 
     sudo ${rsync}/bin/rsync -az /etc/.git /media/daniels/Backup/etc/
     sudo chown daniels:daniels -R /media/daniels/Backup/etc/
     cd /media/daniels/Backup/etc/
-    ${git}/bin/git reset --hard master
+    git reset --hard master
   '';
 }

home/packages/custom/dmenu-scripts/default.nix

@@ -2,7 +2,9 @@
   writeShellApplication,
   dmenu,
   dunst,
-  bc
+  bc,
+  firefox,
+  i3
 }:
 
 let
@@ -58,6 +60,7 @@ let
     name = "dmenu-custom-scripts-system";
 
     runtimeInputs = [
+      i3
       dmenu
       dunst
     ];
@@ -70,6 +73,7 @@ let
 
     runtimeInputs = [
       dmenu
+      firefox
     ];
 
     text = ''

home/packages/custom/push-etckeeper/default.nix

@@ -1,8 +1,15 @@
-{ writeShellApplication }:
+{
+  writeShellApplication,
+  git
+}:
 
 writeShellApplication {
   name = "custom-push-etckeeper";
 
+  runtimeInputs = [
+    git
+  ];
+
   text = ''
     mkdir /tmp/etckeeper
     cd /tmp/etckeeper

home/packages/sqlformat/default.nix

@@ -10,7 +10,12 @@ let
 
 in writeShellApplication {
   name = "sqlformat";
+
+  runtimeInputs = [
+    python
+  ];
+
   text = ''
-    ${python}/bin/python3 -m sqlparse --keywords upper --identifiers lower --reindent_aligned --indent_width 4 <(cat -)
+    python3 -m sqlparse --keywords upper --identifiers lower --reindent_aligned --indent_width 4 <(cat -)
   '';
 }