build(deps): bump taiki-e/install-action in /.github/workflows

Bumps [taiki-e/install-action](https://github.com/taiki-e/install-action) from 2.67.18 to 2.67.30.
- [Release notes](https://github.com/taiki-e/install-action/releases)
- [Changelog](https://github.com/taiki-e/install-action/blob/main/CHANGELOG.md)
- [Commits](taiki-e/install-action@650c5ca...288875d)

---
updated-dependencies:
- dependency-name: taiki-e/install-action
  dependency-version: 2.67.30
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/rust-ci.yml

@@ -117,7 +117,7 @@ jobs:
             cargo-${{ matrix.runner }}-${{ matrix.target }}
 
       - name: Install sccache
-        uses: taiki-e/install-action@650c5ca14212efbbf3e580844b04bdccf68dac31 # v2.67.18
+        uses: taiki-e/install-action@470679bc3a1580072dac4e67535d1aa3a3dcdf51 # v2.68.6
         with:
           tool: sccache
 
@@ -216,7 +216,7 @@ jobs:
             cargo-${{ matrix.runner }}-${{ matrix.target }}-
 
       - name: Install sccache
-        uses: taiki-e/install-action@650c5ca14212efbbf3e580844b04bdccf68dac31 # v2.67.18
+        uses: taiki-e/install-action@470679bc3a1580072dac4e67535d1aa3a3dcdf51 # v2.68.6
         with:
           tool: sccache
 
@@ -225,7 +225,7 @@ jobs:
         run: |
           echo "RUSTC_WRAPPER=sccache" >> "$GITHUB_ENV"
 
-      - uses: taiki-e/install-action@650c5ca14212efbbf3e580844b04bdccf68dac31 # v2.67.18
+      - uses: taiki-e/install-action@470679bc3a1580072dac4e67535d1aa3a3dcdf51 # v2.68.6
         with:
           tool: nextest
           version: 0.9.103