feat: add support for multiple includes on a graph edge

testdata/includes/Taskfile.yml

@@ -6,13 +6,13 @@ includes:
   included_without_dir:
     taskfile:  ./module1
   included_taskfile_without_dir:
-    taskfile:  ./module2/Taskfile.yml
+    taskfile:  ./module1/Taskfile.yml
   included_with_dir:
-    taskfile:  ./module3
-    dir:  ./module3
+    taskfile:  ./module2
+    dir:  ./module2
   included_taskfile_with_dir:
-    taskfile:  ./module4/Taskfile.yml
-    dir:  ./module4
+    taskfile:  ./module2/Taskfile.yml
+    dir:  ./module2
   included_os: ./Taskfile_{{OS}}.yml
 
 tasks:

testdata/includes/module1/Taskfile.yml

@@ -1,6 +1,10 @@
 version: '3'
 
 tasks:
+  gen_dir:
+    cmds:
+      - echo included_directory_without_dir > included_directory_without_dir.txt
+
   gen_file:
     cmds:
       - echo included_taskfile_without_dir > included_taskfile_without_dir.txt

testdata/includes/module2/Taskfile.yml

@@ -3,4 +3,8 @@ version: '3'
 tasks:
   gen_dir:
     cmds:
-      - echo included_directory_without_dir > included_directory_without_dir.txt
+      - echo included_directory_with_dir > included_directory_with_dir.txt
+
+  gen_file:
+    cmds:
+      - echo included_taskfile_with_dir > included_taskfile_with_dir.txt

testdata/includes/module3/Taskfile.yml

@@ -1,6 +0,0 @@
-version: '3'
-
-tasks:
-  gen_file:
-    cmds:
-      - echo included_taskfile_with_dir > included_taskfile_with_dir.txt

testdata/includes/module4/Taskfile.yml

@@ -1,6 +0,0 @@
-version: '3'
-
-tasks:
-  gen_dir:
-    cmds:
-      - echo included_directory_with_dir > included_directory_with_dir.txt