Dependeny versions problematic for older versions, e.y. Yew 0.21

[GunnarBernsteinHH]

Problem
I need to use rust 1.81 for other reasons.
Therefore I use Yew version 0.21, as of crates.io (https://crates.io/crates/yew/0.21.0) it works with Rust 1.64.0.

However, it does not compile:
rustc 1.81.0 is not supported by the following package: indexmap@2.13.0 requires rustc 1.82

Steps To Reproduce
Steps to reproduce the behavior:

1. rustup default 1.81
2. create sample app
3. Change dependendy: yew = {version = "=0.21" , features = ["csr"] }
4. compile (trunk serve)

Expected behavior
Should compile.

Environment:

• Yew version: v0.21
• Rust version: 1.81.0
• OS, if relevant: Linux, probably not relevant

Solution:

Change Cargo.toml
[dependencies.indexmap]
features = ["std"]
version = "=2.11.4"

User can: cargo update indexmap@2.13.0 --precise 2.11.4, but that is hard to research.

Questionnaire

• I'm interested in fixing this myself but don't know where to start
• [x ] I would like to fix and I have a solution (but do not know how to pull)
• I don't have time to fix this right now, but maybe later