update version file

[aadnaane]

update version file in the release branch

[lfaucon]

Should we also in this PR:

(1) Update https://github.com/oracle/agent-spec/blob/main/pyagentspec/src/pyagentspec/versioning.py#L33 to mention 26.1.1 as the new current version?

(2) Update the changelog, such that is has a title saying "Agent Spec 26.1.0" with the content of the version 26.1.0 and the changelog should be reset to empty below the title "Agent Spec |release|" https://github.com/oracle/agent-spec/blob/main/docs/pyagentspec/source/changelog.rst so that it gets filled in the next weeks with the new features for the next release

[lfaucon]

Also, I was expecting this PR to target main, is it not the case?
Do we plan to merge the branch agent-spec-26.1.x onto main?
Sorry, I probably lack awareness of the release process.

[nasseur]

Internal regression succeeded 🍏: Build ID #184

[aadnaane]

@lfaucon I updated the changelog to mention 26.1.0 and add a new section for the next release, for the PR that should target main, I already have another one with the full approval and included the necessary changes.