I've got this error with buildroot-2022.11 when executing make.

Ubuntu 20.04 - added this repo as described in the link

sudo apt update
sudo apt install libc6

It automatically installed 2.35 for me.

You can use following commands to bring in newer version of glibc in ubuntu 20.04, but note that as it is a system package, upgrading it may impact your system.

apt-get install gawk bison gcc make wget tar -y
wget -c https://ftp.gnu.org/gnu/glibc/glibc-2.35.tar.gz
tar -zxvf glibc-2.35.tar.gz && cd glibc-2.35
mkdir glibc-build && cd glibc-build
../configure --prefix=/opt/glibc
make
make install

ITs works for me when i avoid /target directory and now working both version of ubuntu 20.04 and 21.10. Giving thanks to @Charles Duffy and @Herohtar for their important and useful instruction,

CopyFROM ubuntu:21.10
RUN apt-get update && apt-get upgrade -y
RUN apt-get install libssl-dev

RUN apt-get install -y -q build-essential curl
RUN curl https://sh.rustup.rs -sSf | sh -s -- -y
ENV PATH="/root/.cargo/bin:${PATH}"

WORKDIR /command-agent
COPY ./src/. /command-agent/src/
COPY .env /command-agent/
COPY Cargo.toml /command-agent/
COPY Cargo.lock /command-agent/
RUN cargo build --release

EXPOSE 8080
ENTRYPOINT /command-agent/target/release/command-agent

You don't have a high enough version of libc6, that is causing the error.

From How to fix “/lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.14' not found”? – Super User:

That means the program was compiled against glibc version 2.14, and it requires that version to run, but your system has an older version installed. You'll need to either recompile the program against the version of glibc that's on your system, or install a newer version of glibc (the "libc6" package in Debian).

So, you just need to upgrade your libc6 package. All versions of Ubuntu have at least version 2.15 because it's a faily important package (reference).

To upgrade it, use these commands in a terminal:

sudo apt-get update
sudo apt-get install libc6

It should be noted that https://abrok.eu/stockfish/ is not official, author clearly says that the packages were compiled with gcc 11.2/mingw 10 on Ubuntu 21.10.
While you are running 20.04 LTS which is older, so has older libc and other core system components.

I see two possible solutions:

• Official packages from the developer

  The StockFish package for Ubuntu lists the following URL as developer's web-site https://stockfishchess.org . So you should visit https://stockfishchess.org/download/linux/ and then download relevant software distribution. For the time of writing it maybe done programmatically as follows:

  cd ~/Downloads
  wget -c https://stockfishchess.org/files/stockfish_14.1_linux_x64_avx2.zip
  unzip stockfish_14.1_linux_x64_avx2.zip
  cd stockfish_14.1_linux_x64_avx2
  chmod +x stockfish_14.1_linux_x64_avx2
  

  and then run it as ./stockfish_14.1_linux_x64_avx2.

  Note: it runs even on 18.04 LTS, does not complain about libc.

• Some third-party PPA

  Finding PPA for StockFish is possible. It will end with for example StockFish 12.2 deb-package for 20.04 LTS, which may be installed by using below commands:

  sudo add-apt-repository ppa:savoury1/games
  sudo apt-get update
  sudo apt-get install stockfish
  

  Note: I'm not sure about AVX2 optimisation here.

  Reverting to default 11.1 version is possible by using below commands:

  sudo apt-get install ppa-purge
  sudo ppa-purge ppa:savoury1/games