Rust: make ast-generator use mustache templates

This simplifies the code and decouples the code template from the data
that is fed into it.

MODULE.bazel

@@ -70,7 +70,7 @@ use_repo(py_deps, "vendor__anyhow-1.0.44", "vendor__cc-1.0.70", "vendor__clap-2.
 # deps for ruby+rust
 # keep in sync by running `misc/bazel/3rdparty/update_cargo_deps.sh`
 tree_sitter_extractors_deps = use_extension("//misc/bazel/3rdparty:tree_sitter_extractors_extension.bzl", "r")
-use_repo(tree_sitter_extractors_deps, "vendor__anyhow-1.0.94", "vendor__argfile-0.2.1", "vendor__chrono-0.4.39", "vendor__clap-4.5.23", "vendor__dunce-1.0.5", "vendor__either-1.13.0", "vendor__encoding-0.2.33", "vendor__figment-0.10.19", "vendor__flate2-1.0.35", "vendor__glob-0.3.1", "vendor__globset-0.4.15", "vendor__itertools-0.12.1", "vendor__itertools-0.13.0", "vendor__lazy_static-1.5.0", "vendor__log-0.4.22", "vendor__num-traits-0.2.19", "vendor__num_cpus-1.16.0", "vendor__proc-macro2-1.0.92", "vendor__quote-1.0.37", "vendor__ra_ap_base_db-0.0.248", "vendor__ra_ap_cfg-0.0.248", "vendor__ra_ap_hir-0.0.248", "vendor__ra_ap_hir_def-0.0.248", "vendor__ra_ap_hir_expand-0.0.248", "vendor__ra_ap_ide_db-0.0.248", "vendor__ra_ap_intern-0.0.248", "vendor__ra_ap_load-cargo-0.0.248", "vendor__ra_ap_parser-0.0.248", "vendor__ra_ap_paths-0.0.248", "vendor__ra_ap_project_model-0.0.248", "vendor__ra_ap_span-0.0.248", "vendor__ra_ap_stdx-0.0.248", "vendor__ra_ap_syntax-0.0.248", "vendor__ra_ap_vfs-0.0.248", "vendor__rand-0.8.5", "vendor__rayon-1.10.0", "vendor__regex-1.11.1", "vendor__serde-1.0.216", "vendor__serde_json-1.0.133", "vendor__serde_with-3.11.0", "vendor__stderrlog-0.6.0", "vendor__syn-2.0.90", "vendor__tracing-0.1.41", "vendor__tracing-subscriber-0.3.19", "vendor__tree-sitter-0.24.5", "vendor__tree-sitter-embedded-template-0.23.2", "vendor__tree-sitter-json-0.24.8", "vendor__tree-sitter-ql-0.23.1", "vendor__tree-sitter-ruby-0.23.1", "vendor__triomphe-0.1.14", "vendor__ungrammar-1.16.1")
+use_repo(tree_sitter_extractors_deps, "vendor__anyhow-1.0.95", "vendor__argfile-0.2.1", "vendor__chrono-0.4.39", "vendor__clap-4.5.23", "vendor__dunce-1.0.5", "vendor__either-1.13.0", "vendor__encoding-0.2.33", "vendor__figment-0.10.19", "vendor__flate2-1.0.35", "vendor__glob-0.3.1", "vendor__globset-0.4.15", "vendor__itertools-0.12.1", "vendor__itertools-0.13.0", "vendor__lazy_static-1.5.0", "vendor__log-0.4.22", "vendor__mustache-0.9.0", "vendor__num-traits-0.2.19", "vendor__num_cpus-1.16.0", "vendor__proc-macro2-1.0.92", "vendor__quote-1.0.37", "vendor__ra_ap_base_db-0.0.248", "vendor__ra_ap_cfg-0.0.248", "vendor__ra_ap_hir-0.0.248", "vendor__ra_ap_hir_def-0.0.248", "vendor__ra_ap_hir_expand-0.0.248", "vendor__ra_ap_ide_db-0.0.248", "vendor__ra_ap_intern-0.0.248", "vendor__ra_ap_load-cargo-0.0.248", "vendor__ra_ap_parser-0.0.248", "vendor__ra_ap_paths-0.0.248", "vendor__ra_ap_project_model-0.0.248", "vendor__ra_ap_span-0.0.248", "vendor__ra_ap_stdx-0.0.248", "vendor__ra_ap_syntax-0.0.248", "vendor__ra_ap_vfs-0.0.248", "vendor__rand-0.8.5", "vendor__rayon-1.10.0", "vendor__regex-1.11.1", "vendor__serde-1.0.216", "vendor__serde_json-1.0.133", "vendor__serde_with-3.12.0", "vendor__stderrlog-0.6.0", "vendor__syn-2.0.90", "vendor__tracing-0.1.41", "vendor__tracing-subscriber-0.3.19", "vendor__tree-sitter-0.24.5", "vendor__tree-sitter-embedded-template-0.23.2", "vendor__tree-sitter-json-0.24.8", "vendor__tree-sitter-ql-0.23.1", "vendor__tree-sitter-ruby-0.23.1", "vendor__triomphe-0.1.14", "vendor__ungrammar-1.16.1")
 
 http_archive = use_repo_rule("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")