[Python] Update python-pydantic-v1 generator to respect the --git-host argument (#19404)

* Update pyproject.mustache

chore(pyproject): replace static `github.com` with variable `{{{gitHost}}}`

* chore: follow contribution guidelines

samples/openapi3/client/petstore/python-pydantic-v1/git_push.sh

@@ -9,7 +9,7 @@ release_note=$3
 git_host=$4
 
 if [ "$git_host" = "" ]; then
-    git_host="github.com"
+    git_host="GIT_HOST"
     echo "[INFO] No command line input provided. Set \$git_host to $git_host"
 fi