add support for PEP 621: use poetry-core from main branch and bump version to 2.0.0.dev0 (#9135)

Author: radoering

poetry.lock

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "poetry"
-version = "1.9.0.dev0"
+version = "2.0.0.dev0"
 description = "Python dependency management and packaging made easy."
 authors = ["Sébastien Eustace <[email protected]>"]
 maintainers = [
@@ -31,7 +31,7 @@ Changelog = "https://python-poetry.org/history/"
 [tool.poetry.dependencies]
 python = "^3.8"
 
-poetry-core = "1.9.0"
+poetry-core = { git = "https://github.com/python-poetry/poetry-core.git", branch = "main" }
 poetry-plugin-export = "^1.8.0"
 build = "^1.2.1"
 cachecontrol = { version = "^0.14.0", extras = ["filecache"] }