[CI] Bump peter-evans/create-pull-request from 6.0.2 to 6.0.3 (#1107)

Bumps [peter-evans/create-pull-request](https://github.com/peter-evans/create-pull-request) from 6.0.2 to 6.0.3.
- [Release notes](https://github.com/peter-evans/create-pull-request/releases)
- [Commits](peter-evans/create-pull-request@70a41ab...c55203c)

---
updated-dependencies:
- dependency-name: peter-evans/create-pull-request
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/roll-pinned-toolchain-versions.yml

@@ -103,7 +103,7 @@ jobs:
           fi
 
       - name: Submit PR
-        uses: peter-evans/create-pull-request@70a41aba780001da0a30141984ae2a0c95d8704e # v6.0.2
+        uses: peter-evans/create-pull-request@c55203cfde3e5c11a452d352b4393e68b85b4533 # v6.0.3
         with:
           commit-message: "[ci] Roll pinned ${{ matrix.toolchain }} toolchain"
           author: Google PR Creation Bot <[email protected]>
@@ -133,7 +133,7 @@ jobs:
           # Update the `kani-version:` argument in-place.
           sed -i -E -e "s/^( *kani-version:)( [0-9]+\.[0-9]+\.[0-9]+)/\1 $KANI_LATEST/" .github/workflows/ci.yml
       - name: Submit PR
-        uses: peter-evans/create-pull-request@70a41aba780001da0a30141984ae2a0c95d8704e # v6.0.2
+        uses: peter-evans/create-pull-request@c55203cfde3e5c11a452d352b4393e68b85b4533 # v6.0.3
         with:
           commit-message: "[ci] Roll pinned Kani version"
           author: Google PR Creation Bot <[email protected]>