[gha workflow] use tot android swift-foundation (#819)

Author: hyp

.github/workflows/swift-toolchain.yml

@@ -1874,19 +1874,11 @@ jobs:
           path: ${{ github.workspace }}/SourceCache/swift-corelibs-foundation
           show-progress: false
       - uses: actions/checkout@v4
-        if: matrix.os != 'Android'
         with:
           repository: apple/swift-foundation
           ref: ${{ inputs.swift_foundation_revision }}
           path: ${{ github.workspace }}/SourceCache/swift-foundation
           show-progress: false
-      - uses: actions/checkout@v4
-        if: matrix.os == 'Android'
-        with:
-          repository: hyp/swift-foundation
-          ref: android-wmo-merged
-          path: ${{ github.workspace }}/SourceCache/swift-foundation
-          show-progress: false
       - uses: actions/checkout@v4
         with:
           repository: apple/swift-foundation-icu