Toolchain update for Windows builds of DuckDB

[staticlibs]

Hi R client maintainers!

We are changing the toolchain that is used on DuckDB CI to produce Windows binaries, details:

• Well-defined environment for MinGW builds duckdb#21371
• Update environment for Windows builds extension-ci-tools#343

Currently the following MinGW build is used:

https://github.com/niXman/mingw-builds-binaries/releases/download/14.2.0-rt_v12-rev0/x86_64-14.2.0-release-posix-seh-ucrt-rt_v12-rev0.7z

The the GCC version 14.2 was chosen to stay closer to release Linux builds.

We can change the toolchain if necessary, please let us know if it is better to use different kind/version of MinGW binaries. Besides R these binaries are also used by Golang client.

[krlmlr]

Thanks for reaching out. R has very specific requirements, defined by the Rtools toolchain and different across R versions.

Are you familiar with Rtools? Should we find a time to chat?

It would be exciting to see extensions work where the Windows support has been weak in the past.

[abfleishman]

Ooo would this help enable some of the extensions that don't work on windows listed in #100!?

[Upipa]

If I understood well this would enable the motherduck extension. I have a blocked project for this extension missing :(