8 files declare their use of SolrBackendInterface in Search API Solr 8.2

LocalActionAccessCheck.php in src/Access/LocalActionAccessCheck.php

SearchApiSolrBackend.php in src/Plugin/search_api/backend/SearchApiSolrBackend.php

SearchApiSolrTest.php in tests/src/Kernel/SearchApiSolrTest.php

search_api_solr.module in ./search_api_solr.module

SolrAdminAccessCheck.php in modules/search_api_solr_admin/src/Access/SolrAdminAccessCheck.php

SolrAdminForm.php in modules/search_api_solr_admin/src/Form/SolrAdminForm.php

SolrFieldTypeListBuilder.php in src/Controller/SolrFieldTypeListBuilder.php

SolrReloadCoreForm.php in modules/search_api_solr_admin/src/Form/SolrReloadCoreForm.php