chore(deps): update taiki-e/install-action digest to c6dc131 (#103)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[taiki-e/install-action](https://redirect.github.com/taiki-e/install-action)
| action | digest | `678b06b` -> `c6dc131` |

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### Configuration

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Automerge - At any time (no schedule defined).

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again.

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.github/workflows/install-mdbook/action.yml

@@ -27,7 +27,7 @@ runs:
       shell: bash
 
     - name: Install dependencies
-      uses: taiki-e/install-action@678b06b887cdbf44fa0601e5915f865e17c2241d # v2
+      uses: taiki-e/install-action@c6dc131d2c4291552cafb840290190a53b2cd937 # v2
       with:
         tool: mdbook@${{ steps.mdbook-version.outputs.version }},mdbook-pandoc@${{ steps.mdbook-pandoc-version.outputs.version }},mdbook-last-changed@${{ steps.mdbook-last-changed-version.outputs.version }}