The action queries GitHub API with $GITHUB_TOKEN which is a Gitea token
on this runner — it gets a 401.

Assisted-by: GLM-5 via pi

diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index bb7735e..04725db 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -14,7 +14,11 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
         with:
           persist-credentials: false
-      - uses: facebook/install-dotslash@1e4e7b3e07eaca387acb98f1d4720e0bee8dbb6a # v2
+      # Can't use facebook/install-dotslash action because it queries the
+      # GitHub API using $GITHUB_TOKEN, which is a Gitea token on this runner.
+      - run: |
+          curl -sL https://github.com/facebook/dotslash/releases/download/v0.5.9/dotslash-linux-musl.x86_64.tar.gz |
+            tar xz -C /usr/local/bin
       - run: curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
       - run: echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
       - run: echo "$PWD/bin" >> "$GITHUB_PATH"
@@ -33,7 +37,11 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
         with:
           persist-credentials: false
-      - uses: facebook/install-dotslash@1e4e7b3e07eaca387acb98f1d4720e0bee8dbb6a # v2
+      # Can't use facebook/install-dotslash action because it queries the
+      # GitHub API using $GITHUB_TOKEN, which is a Gitea token on this runner.
+      - run: |
+          curl -sL https://github.com/facebook/dotslash/releases/download/v0.5.9/dotslash-linux-musl.x86_64.tar.gz |
+            tar xz -C /usr/local/bin
       - run: echo "$PWD/bin" >> "$GITHUB_PATH"
       # Can't use zizmorcore/zizmor-action because it doesn't support
       # auditing .gitea/workflows/ — it rejects them as invalid inputs.