ci: temporarily disable riscv64-linux

GitHub sucks:

    Sep 20 20:49:21 ganymede runsvc.sh[82817]: An error occured: Runner version v2.326.0 is deprecated and cannot receive messages.
    Sep 20 20:49:21 ganymede runsvc.sh[82817]: Runner listener exited with error code 1
    Sep 20 20:49:21 ganymede runsvc.sh[82817]: Runner listener exit with terminated error, stop the service, no retry needed.

.github/workflows/ci-pr-riscv64-linux.yaml

@@ -1,35 +0,0 @@
-name: ci-pr-riscv64-linux
-on:
-  pull_request:
-    types:
-      - labeled
-      - opened
-      - reopened
-      - synchronize
-      - unlabeled
-concurrency:
-  # Cancels pending runs when a PR gets updated.
-  group: riscv64-linux-${{ github.head_ref || github.run_id }}-${{ github.actor }}
-  cancel-in-progress: true
-permissions:
-  # Sets permission policy for `GITHUB_TOKEN`
-  contents: read
-jobs:
-  riscv64-linux-debug:
-    if: contains(github.event.pull_request.labels.*.name, 'ci-riscv64-linux')
-    timeout-minutes: 420
-    runs-on: [self-hosted, Linux, riscv64]
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Build and Test
-        run: sh ci/riscv64-linux-debug.sh
-  riscv64-linux-release:
-    if: contains(github.event.pull_request.labels.*.name, 'ci-riscv64-linux')
-    timeout-minutes: 420
-    runs-on: [self-hosted, Linux, riscv64]
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Build and Test
-        run: sh ci/riscv64-linux-release.sh

.github/workflows/ci.yaml

@@ -50,24 +50,6 @@ jobs:
         uses: actions/checkout@v4
       - name: Build and Test
         run: sh ci/aarch64-linux-release.sh
-  riscv64-linux-debug:
-    if: github.event_name == 'push'
-    timeout-minutes: 420
-    runs-on: [self-hosted, Linux, riscv64]
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Build and Test
-        run: sh ci/riscv64-linux-debug.sh
-  riscv64-linux-release:
-    if: github.event_name == 'push'
-    timeout-minutes: 420
-    runs-on: [self-hosted, Linux, riscv64]
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - name: Build and Test
-        run: sh ci/riscv64-linux-release.sh
   x86_64-macos-release:
     runs-on: "macos-13"
     env: