Compile error due to use of unstable feature

[marcbrevoort-cyberhive]

When installing with cargo +1.81.0 install grcov --locked I get this error:

09:58:17  error[E0658]: use of unstable library feature 'iter_repeat_n'
09:58:17     --> /home/ubuntu/.cargo/registry/src/index.crates.io-6f17d22bba15001f/tabled-0.19.0/src/tables/table_pool.rs:894:20
09:58:17      |
09:58:17  894 |         buf.extend(repeat_n(c, width));
09:58:17      |                    ^^^^^^^^
09:58:17      |
09:58:17      = note: see issue #104434 <https://github.com/rust-lang/rust/issues/104434> for more information
09:58:17  
09:58:19     Compiling crossbeam-channel v0.5.15
09:58:19  For more information about this error, try `rustc --explain E0658`.
09:58:19  error: could not compile `tabled` (lib) due to 28 previous errors
09:58:19  warning: build failed, waiting for other jobs to finish...
09:58:24  error: failed to compile `grcov v0.10.0`, intermediate artifacts can be found at `/home/ubuntu/tmp/cargo-installXIhUT3`.

FWIW cargo install grcov --locked (which defaults to rust 1.85.0) does not raise this error, but an upgrade to rustc 1.85.0 isn't an option for us yet.