Downgrade GNU Arm Toolchain to 10.3-2021.10

This is because of this bug:
https://community.arm.com/support-forums/f/compilers-and-libraries-forum/52623/gcc-11-2-arm-none-eabi-internal-compiler-error-illegal-instruction
It is causing some of the GitHub Actions builds to fail.

doc/MemoryAnalysis.md

@@ -51,9 +51,9 @@ Puncover is really easy to install:
     - `python -m virtualenv venv` 
     - `source venv/bin/activate`
  - Install : `pip install .`
- - Run : `puncover --gcc_tools_base=/path/to/gcc-arm-11.2-2022.02-x86_64-arm-none-eabi/bin/arm-none-eabi- --elf_file /path/to/build/directory/src/pinetime-app-1.1.0.out --src_root /path/to/sources --build_dir /path/to/build/directory`
+ - Run : `puncover --gcc_tools_base=/path/to/gcc-arm-none-eabi-10.3-2021.10/bin/arm-none-eabi- --elf_file /path/to/build/directory/src/pinetime-app-1.1.0.out --src_root /path/to/sources --build_dir /path/to/build/directory`
      - Replace
-         * `/path/to/gcc-arm-11.2-2022.02-x86_64-arm-none-eabi/bin` with the path to your gcc-arm-none-eabi toolchain
+         * `/path/to/gcc-arm-none-eabi-10.3-2021.10/bin` with the path to your gcc-arm-none-eabi toolchain
          * `/path/to/build/directory/src/pinetime-app-1.1.0.out` with the path to the binary generated by GCC (.out file)
          * `/path/to/sources` with the path to the root folder of the sources (checkout directory)
         * `/path/to/build/directory` with the path to the build directory