Add x64 MacOS builds of OpenOCD and Risc-V toolchain

Update Risc-V toolchain and OpenOCD builds

Use ubuntu-22.04 runner for Linux builds, rather than ubuntu-latest

This release does not contain Risc-V toolchain or OpenOCD builds - see v2.0.0-5 for the latest versions of the Risc-V toolchain, and v2.1.0-0 for the latest versions of OpenOCD

Use SDK and picotool 2.1.1

This release does not contain Risc-V toolchain or OpenOCD builds - see v2.0.0-5 for the latest versions of the Risc-V toolchain, and v2.1.0-0 for the latest versions of OpenOCD

Use SDK and picotool 2.1.0

This release does not contain Risc-V toolchain builds - see v2.0.0-5 for the latest versions of those

Statically link Risc-V toolchain on Linux (#4)

Fix invalid filenames in Windows OpenOCD, which caused issues with some decompression libraries (#5)

Only include libgpiod in arm64 Linux OpenOCD builds (raspberrypi/pico-vscode#84)

This release does not contain Risc-V toolchain builds - see v2.0.0-2 for the latest versions of those

Add libgpiod to Linux OpenOCD builds (#2)

This release does not contain Risc-V toolchain builds - see v2.0.0-2 for the latest versions of those

Fix OpenOCD build

Add Risc-V toolchain builds for all platforms

Windows and MacOS x64 builds use pre-built toolchains from Embecosm, with the correct rv32 lib copied in, rather than compiling from source