The RUNTIME_DIR 'runtime' does not look like a Cargo project with version 0.9.0 or later

[atodorov]

Switching from v0.8.0 to 0.9.0 or later seems to fail with:

Srtool build of chain creditcoin
  ║ 🧰 Substrate Runtime Toolbox - srtool v0.12.0 🧰
  ║ - by Chevdor -
  info: using existing install for '1.73.0-x86_64-unknown-linux-gnu'
  info: override toolchain for '/build' set to '1.73.0-x86_64-unknown-linux-gnu'
  ║
  ║ 1.73.0-x86_64-unknown-linux-gnu unchanged - rustc 1.73.0 (cc66ad468 2023-10-03)
  ║
  ║ 🏗 Building creditcoin3-runtime as release using rustc 1.73.0 (cc66ad468 2023-10-03)
  ║ ⏳ That can take a little while, be patient... subsequent builds may be faster.
  ║ Since you have to wait a little, you may want to learn more about Substrate runtimes:
  ║ https://docs.substrate.io/learn/architecture/
  toml: No such file or directory (os error 2)
  ║ !!! The RUNTIME_DIR 'runtime' does not look like a Cargo project. Is it pointing to the folder of your runtime crate?
  parse error: Invalid numeric literal at line 1, column 4

Works fine with version 0.8.0.

Full logs at: https://github.com/gluwa/creditcoin3/actions/runs/7715917088/job/21031526965?pr=195

Latest PR switching from 0.8.0 to 0.9.2 -> https://github.com/gluwa/creditcoin3/pull/195 (there are closed PRs in the same repo trying to upgrade to 0.9.0 and 0.9.1 but logs have probably expired).