ci: delete gi-docgen package in each repository

As of a commit 9daef10 ("doc: annotate error domain available in
gi-docgen 2023.1"), the version of gi-docgen package in each respository
includes some bugs to generate error domain. Nowadays it has been
upgraded.

This commit deletes the workaround in github workflow.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

.github/workflows/build.yml

@@ -16,21 +16,9 @@ jobs:
         dnf -y install gi-docgen python3-gobject
     - name: Checkout repository.
       uses: actions/checkout@v4
-    - name: Create gi-docgen.wrap in subproject directory
-      run: |
-        mkdir subprojects
-        cat > subprojects/gi-docgen.wrap << EOF
-        [wrap-git]
-        directory = gi-docgen
-        url = https://gitlab.gnome.org/GNOME/gi-docgen.git
-        revision = 2023.1
-        depth = 1
-        
-        [provide]
-        program_names = gi-docgen
-        EOF
     - name: Create hinawa.wrap in subproject directory
       run: |
+        mkdir subprojects
         cat > subprojects/hinawa.wrap << EOF
         [wrap-git]
         directory = libhinawa
@@ -71,21 +59,9 @@ jobs:
         DEBIAN_FRONTEND=noninteractive apt-get install -y gi-docgen python3-gi
     - name: Checkout repository.
       uses: actions/checkout@v4
-    - name: Create gi-docgen.wrap in subproject directory
-      run: |
-        mkdir subprojects
-        cat > subprojects/gi-docgen.wrap << EOF
-        [wrap-git]
-        directory = gi-docgen
-        url = https://gitlab.gnome.org/GNOME/gi-docgen.git
-        revision = 2023.1
-        depth = 1
-        
-        [provide]
-        program_names = gi-docgen
-        EOF
     - name: Create hinawa.wrap in subproject directory
       run: |
+        mkdir subprojects
         cat > subprojects/hinawa.wrap << EOF
         [wrap-git]
         directory = libhinawa