sphinx_immaterial/search_adapt.py: AttributeError: 'IndexBuilder' object has no attribute 'env' with Sphinx 8.2.0

[holmboe]

This failure started coming after the release of Sphinx 8.2.0:

Versions
========
* Platform:         linux; (Linux-5.15.0-126-generic-x86_64-with-glibc2.36)
* Python version:   3.11.11 (CPython)
* Sphinx version:   8.2.0
* Docutils version: 0.21.2
* Jinja2 version:   3.1.5
* Pygments version: 2.19.1
Last Messages
=============
    copying images... [ 96%]
    docs/assets/wiki-edit-button.png
    copying images... [100%]
    docs/assets/wiki-new-page-button.png
    dumping search index in English (code: en)...
    failed
Loaded Extensions
=================
* sphinx.ext.mathjax (8.2.0)
* alabaster (1.0.0)
* sphinxcontrib.applehelp (2.0.0)
* sphinxcontrib.devhelp (2.0.0)
* sphinxcontrib.htmlhelp (2.1.0)
* sphinxcontrib.serializinghtml (2.0.0)
* sphinxcontrib.qthelp (2.0.0)
* sphinx.ext.extlinks (8.2.0)
* linuxdoc.rstFlatTable (3.0)
* sphinx_immaterial.css_and_javascript_bundles (unknown version)
* sphinx_immaterial.external_resource_cache (unknown version)
* sphinx_immaterial.google_fonts (unknown version)
* sphinx_immaterial.local_mathjax (unknown version)
* sphinx_immaterial.apidoc.apidoc_formatting (unknown version)
* sphinx_immaterial.apidoc.python.parameter_objects (unknown version)
* sphinx_immaterial.apidoc.python.strip_property_prefix (unknown version)
* sphinx_immaterial.apidoc.python.type_annotation_transforms (unknown version)
* sphinx_immaterial.apidoc.python.strip_self_and_return_type_annotations (unknown version)
* sphinx_immaterial.apidoc.python.default (unknown version)
* sphinx_immaterial.apidoc.cpp.signodes (unknown version)
* sphinx_immaterial.apidoc.cpp.strip_namespaces_from_signatures (unknown version)
* sphinx_immaterial.apidoc.cpp.cpp_resolve_c_xrefs (unknown version)
* sphinx_immaterial.apidoc.cpp.default (unknown version)
* sphinx_immaterial.nav_adapt (unknown version)
* sphinx_immaterial.postprocess_html (unknown version)
* sphinx_immaterial.apidoc.object_description_options (unknown version)
* sphinx_immaterial.apidoc.object_toc (unknown version)
* sphinx_immaterial.search_adapt (unknown version)
* sphinx_immaterial.apidoc.wrap_signatures (unknown version)
* sphinx_immaterial.apidoc.generic_synopses (unknown version)
* sphinx_immaterial.content_tabs (unknown version)
* sphinx_immaterial.mermaid_diagrams (unknown version)
* sphinx_immaterial.task_lists (unknown version)
* sphinx_immaterial.code_annotations (unknown version)
* sphinx_immaterial.default_literal_role (unknown version)
* sphinx_immaterial.highlight_push_pop (unknown version)
* sphinx_immaterial.inline_icons (unknown version)
* sphinx_immaterial.custom_admonitions (unknown version)
* sphinx_immaterial (unknown version)
* sphinx_design (0.6.1)
* myst_parser (4.0.1)
* sphinxcontrib.bibtex (2.6.3)
* sphinxcontrib.plantuml (unknown version)
Traceback
=========
      File "/usr/local/lib/python3.11/site-packages/sphinx_immaterial/search_adapt.py", line 67, in get_objects
        all_objs = _get_all_objects(self.env)
                                    ^^^^^^^^
    AttributeError: 'IndexBuilder' object has no attribute 'env'