Remove temporary win32.aarch64 environment from exe-feature

[HannesWell]

Because the win32.aarch64 environment is now generally activated for the entire SDK (see https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/pull/1917) it is not necessary anymore to activate it only for the equinox.executable feature (temporarily required in https://github.com/eclipse-equinox/equinox/pull/559).

Part of https://github.com/eclipse-platform/eclipse.platform.releng.aggregator/issues/577

[github-actions[bot]]

Test Results

  660 files  ±0    660 suites  ±0   1h 11m 42s :stopwatch: - 2m 37s 2 195 tests ±0  2 148 :white_check_mark: ±0   47 :zzz: ±0  0 :x: ±0  6 729 runs  ±0  6 586 :white_check_mark: ±0  143 :zzz: ±0  0 :x: ±0 

Results for commit 62272e71. ± Comparison against base commit 1b7612a2.