Remove unused org.eclipse.swt.gtk.linux.loongarch64 fragment

[HannesWell]

It is neither built nor published and currently just dead configuration that still needs to be updated regularly.

It was introduced via Bug 578951, but the last attempt to make it work was abandoned in

• Updated the code related to LoongArch and added the necessary so files. #1135

If desired, it can be added back at any time.

[github-actions]

Test Results

  188 files  ±0    188 suites  ±0   29m 3s ⏱️ + 3m 16s
4 732 tests ±0  4 709 ✅ ±0   23 💤 ±0  0 ❌ ±0 
6 861 runs  ±0  6 698 ✅ ±0  163 💤 ±0  0 ❌ ±0 

Results for commit 722ad01. ± Comparison against base commit f49428e.

♻️ This comment has been updated with latest results.

[HeikoKlare]

I am fine with removing this fragment.

I see some places that should probably be adapted as well:

• Agents.md information about the architecture being supported:

  eclipse.platform.swt/AGENTS.md

  Line 46 in f49428e

  - **Supported Architectures**: x86_64, aarch64, loongarch64, ppc64le, riscv64

• Architecture being mentioned in the readme:

  eclipse.platform.swt/bundles/org.eclipse.swt/Readme.md

  Lines 25 to 26 in f49428e

  	These examples refer to the architecture `x86_64` but there are other projects for
  	other architectures, like `aarch64` (or `loongarch64` / `ppc64le` for Linux).

• Binaries build script case for the architecture:

  eclipse.platform.swt/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/build.sh

  Lines 130 to 137 in f49428e

  	"linux.loongarch64")
  	if [ "${CC}" = "" ]; then
  	export CC=gcc
  	fi
  	if [ "${PKG_CONFIG_PATH}" = "" ]; then
  	export PKG_CONFIG_PATH="/usr/lib64/pkgconfig/"
  	fi
  	;;

[HannesWell]

I am fine with removing this fragment.

I see some places that should probably be adapted as well:

Thanks. These places are adapted now.

[akurtakov]

This is related to eclipse-platform/eclipse.platform.releng.aggregator#2187 .
I can't make my mind on this issues as I have been on the other side back in the days for ~2 years with initial Linux/arm64 builds before it became part official build of Eclipse. On one side making it easier for people to build on other architectures helps growing the community but only if there is someone truly active to drive such a port.