feat: ✨ make efibootmgr and sbsign optional dependencies

src/snap-pac-uki.fish

@@ -7,10 +7,8 @@ end
 
 function check_deps -d "checks if all dependencies are available"
     set -l dependencies \
-        "efibootmgr" \
         "jq" \
         "rg" \
-        "sbsign" \
         "sed" \
         "snapper" \
 
@@ -21,6 +19,18 @@ function check_deps -d "checks if all dependencies are available"
             error "missing depenency: $dep"
         end
     end
+
+    which "efibootmgr" >/dev/null 2>/dev/null
+    if test $status != "0" -a $CFG_EFI = "yes"
+        set -g CFG_EFI "no"
+        echo "CFG_EFI overwriten to \"no\": 'efibootmgr' not available"
+    end
+
+    which "sbsign" >/dev/null 2>/dev/null
+    if test $status != "0" -a $CFG_EFI = "yes"
+        set -g CFG_SECUREBOOT "no"
+        echo "CFG_SECUREBOOT overwriten to \"no\": 'sbsign' not available"
+    end
 end
 
 function find_tasks -d "finds out what the program needs to do"
@@ -122,9 +132,9 @@ end
 
 function main
     # prepare for execution
-    check_deps
     source "/etc/snap-pac-uki/config.fish"
     config
+    check_deps
 
     switch $argv[1]
         case "snapshots"