Set VERSION to 1.14.0-DEV (#59818)

This PR won't be merged before Monday, October 27, 2025, per the [1.13
feature
freeze](https://discourse.julialang.org/t/julia-1-13-feature-freeze-monday-october-27-2025/133087?u=dilumaluthge).

After this PR has been merged, the `release-1.13` branch will be created
off of the commit immediately prior to this commit.

TODO list before merging this PR:
- [x] Wait until Monday, October 27, 2025
- [x] Create the `julia-release-1.13` Buildkite pipeline ([instructions
here](https://github.com/JuliaCI/julia-buildkite/blob/main/devdocs/create-new-release-pipeline.md)).
I'll do that sometime this week or next week.
    - Done: https://buildkite.com/julialang/julia-release-1-dot-13

TODO list after merging this PR:
- [ ] Create the `release-1.13` branch in this repo.
- [ ] Open the "Backports for Julia 1.13" PR in this repo.
- [ ] Create a new branch named `release-julia-1.13` in the
[JuliaCI/julia-buildkite
repo](https://github.com/JuliaCI/julia-buildkite).
- [ ] Make a PR (against the `backports-release-1.13` branch in this
repo) to use the `release-julia-1.13` branch from the
JuliaCI/julia-buildkite repo.

Author: DilumAluthge

VERSION

@@ -1 +1 @@
-1.13.0-DEV
+1.14.0-DEV