Bump DeterminateSystems/update-flake-lock

Bumps the all-github-actions group with 1 update: [DeterminateSystems/update-flake-lock](https://github.com/determinatesystems/update-flake-lock).


Updates `DeterminateSystems/update-flake-lock` from 25 to 26
- [Release notes](https://github.com/determinatesystems/update-flake-lock/releases)
- [Commits](DeterminateSystems/update-flake-lock@v25...v26)

---
updated-dependencies:
- dependency-name: DeterminateSystems/update-flake-lock
  dependency-version: '26'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: all-github-actions
...

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

Author: dependabot[bot]

.github/workflows/flake-update.yml

@@ -19,7 +19,7 @@ jobs:
           nix develop --command \
             gomod2nix generate
       - name: Update flake.lock
-        uses: DeterminateSystems/update-flake-lock@v25
+        uses: DeterminateSystems/update-flake-lock@v26
         with:
           token: ${{ secrets.GH_TOKEN_FOR_FLAKE_UPDATE }}
           pr-title: "Update flake.lock"