fix(suse): update pygit2 package name

On modern SUSE distributions, Python module package names
will only resolve with the python3- prefix.

Signed-off-by: Georg Pfuetzenreuter <georg.pfuetzenreuter@suse.com>

salt/osfamilymap.yaml

   pkgrepo_humanname: 'Salt releases for SLE-based SUSE products (openSUSE_{{ opensuse_repo_suffix }})'
   pkgrepo: 'https://download.opensuse.org/repositories/systemsmanagement:/saltstack/openSUSE_{{ opensuse_repo_suffix }}/'
   key_url: 'https://download.opensuse.org/repositories/systemsmanagement:/saltstack/openSUSE_{{ opensuse_repo_suffix }}/repodata/repomd.xml.key'
-  pygit2: python-pygit2
+  pygit2: python3-pygit2
   pyinotify: python-pyinotify
   gitfs:
     pygit2:

test/integration/default/files/_mapdata/opensuse-15.yaml

     pkgrepo: https://download.opensuse.org/repositories/systemsmanagement:/saltstack/openSUSE_Leap_15.3/
     pkgrepo_humanname: Salt releases for SLE-based SUSE products (openSUSE_Leap_15.3)
     py_ver: py3
-    pygit2: python-pygit2
+    pygit2: python3-pygit2
     pyinotify: python-pyinotify
     python_dulwich: python-dulwich
     python_git: python-git

test/integration/default/files/_mapdata/opensuse-tumbleweed.yaml

     pkgrepo: https://download.opensuse.org/repositories/systemsmanagement:/saltstack/openSUSE_Tumbleweed/
     pkgrepo_humanname: Salt releases for SLE-based SUSE products (openSUSE_Tumbleweed)
     py_ver: py3
-    pygit2: python-pygit2
+    pygit2: python3-pygit2
     pyinotify: python-pyinotify
     python_dulwich: python-dulwich
     python_git: python-git