Memory leak in test `tests::can_load_grammar`

[icmccorm]

Valgrind reports the following memory leak when running the test tests::can_load_grammar.

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.12s

       Error leaked 24.0 kiB in 1 block
        Info at calloc
             at hashmap_create (src/uthash.h:199)
             at get_tag_map (src/uthash.h:582)
             at tree_sitter_svelte_external_scanner_create (src/scanner.c:408)
             at ts_parser_set_language (src/./parser.c:1794)
             at tree_sitter::Parser::set_language (lib.rs:363)
             at tree_sitter_svelte::tests::can_load_grammar (lib.rs:72)
             at tree_sitter_svelte::tests::can_load_grammar::{{closure}} (lib.rs:70)
             at core::ops::function::FnOnce::call_once (function.rs:250)
             at test::__rust_begin_short_backtrace
             at test::types::RunnableTest::run
             at test::run_test_in_process
     Summary Leaked 24.0 kiB total