[stable-1] Declare antsibull-core 1.x.y End of Life (#107)

* Declare 1.x.y EOL.

* Rearrange sentences.

README.md

@@ -22,7 +22,7 @@ antsibull-core is covered by the [Ansible Code of Conduct](https://docs.ansible.
 
 From version 1.0.0 on, antsibull-core sticks to semantic versioning and aims at providing no backwards compatibility breaking changes during a major release cycle. We might make exceptions from this in case of security fixes for vulnerabilities that are severe enough.
 
-The current major version is 2.x.y. Development for 2.x.y occurs on the `main` branch. 2.x.y mainly differs from 1.x.y by dropping support for Python 3.6, 3.7, and 3.8. It deprecates several compatibility functions for older Python versions that are no longer needed; see the changelog for details. 1.x.y is still developed on the `stable-1` branch, but only security fixes, major bugfixes, and other changes that are absolutely necessary for the other antsibull projects will be backported.
+The current major version is 2.x.y. Development for 2.x.y occurs on the `main` branch. 1.x.y is now End of Life and was developed on the `stable-1` branch. 2.x.y mainly differs from 1.x.y by dropping support for Python 3.6, 3.7, and 3.8. It deprecates several compatibility functions for older Python versions that are no longer needed; see the changelog for details.
 
 ## Creating a new release:
 

changelogs/fragments/1.7.0.yml

@@ -0,0 +1,4 @@
+release_summary: |
+  Final 1.x.y release of antsibull-core.
+
+  antsibull-core 1.x.y is End of Life. Please upgrade to antsibull-core 2.x.y.

pyproject.toml

@@ -8,7 +8,7 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.poetry]
 name = "antsibull-core"
-version = "1.6.0.post0"
+version = "1.7.0"
 description = "Tools for building the Ansible Distribution"
 authors = ["Toshio Kuratomi <[email protected]>", "Felix Fontein <[email protected]>"]
 license = "GPL-3.0-or-later"