1.43.0

Added

• Add [default] attribute (#2878 by casey)
• Do not ascend above --ceiling when looking for justfile (#2870 by casey)

Misc

• Don't generate completions at runtime (#2896 by casey)
• Update softprops/action-gh-release to 2.3.3 (#2879 by app/dependabot)
• Add submodule alias and dependency targets to grammar (#2877 by casey)
• Bump actions/checkout to v5 (#2864 by app/dependabot)
• Fix Windows PATH_SEP value in readme (#2859 by casey)
• Fix lints for Rust 1.89 (#2860 by casey)
• Note that Debian 13 has been released (#2856 by sblondon)
• Mention just-mcp in readme (#2843 by casey)
• Expand Windows instructions in readme (#2842 by casey)
• Note [parallel] attribute in parallelism section (#2837 by casey)