chore(deps): bump the actions group with 2 updates

Bumps the actions group with 2 updates: [actions/cache](https://github.com/actions/cache) and [dawidd6/action-send-mail](https://github.com/dawidd6/action-send-mail).


Updates `actions/cache` from 5.0.5 to 6.1.0
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@27d5ce7...55cc834)

Updates `dawidd6/action-send-mail` from 6e502825a508b867ab2954ad6343b68787624c01 to 994f270325d4f7257aff241a35488ef54ba364a4
- [Release notes](https://github.com/dawidd6/action-send-mail/releases)
- [Commits](dawidd6/action-send-mail@6e50282...994f270)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: 6.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: dawidd6/action-send-mail
  dependency-version: 994f270325d4f7257aff241a35488ef54ba364a4
  dependency-type: direct:production
  dependency-group: actions
...

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

Author: dependabot[bot]

.github/workflows/casket-pages.yml

@@ -35,7 +35,7 @@ jobs:
           cabal-version: '3.10'
 
       - name: Cache Cabal
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: |
             ~/.cabal/packages

.github/workflows/compilation_tests.yml

@@ -54,19 +54,19 @@ jobs:
           toolchain: ${{ matrix.rust }}
 
       - name: Cache cargo registry
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: ~/.cargo/registry
           key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
 
       - name: Cache cargo index
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: ~/.cargo/git
           key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
 
       - name: Cache cargo build
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: impl/rust-cli/target
           key: ${{ runner.os }}-cargo-build-${{ matrix.rust }}-${{ hashFiles('**/Cargo.lock') }}

.github/workflows/idris-verification.yml

@@ -60,7 +60,7 @@ jobs:
 
       - name: Cache Idris2 install
         id: idris2-cache
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: ~/.idris2
           key: idris2-0.8.0-${{ runner.os }}-v1

.github/workflows/lean-verification.yml

@@ -45,7 +45,7 @@ jobs:
           toolchain: stable
 
       - name: Cache Lean build
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: proofs/lean4/.lake
           key: ${{ runner.os }}-lean-${{ hashFiles('proofs/lean4/lakefile.lean', 'proofs/lean4/lean-toolchain') }}

.github/workflows/push-email-notify.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Send push notification email
-        uses: dawidd6/action-send-mail@6e502825a508b867ab2954ad6343b68787624c01 # pinned
+        uses: dawidd6/action-send-mail@994f270325d4f7257aff241a35488ef54ba364a4 # pinned
         with:
           server_address: ${{ secrets.SMTP_HOST }}
           server_port: ${{ secrets.SMTP_PORT }}

.github/workflows/validation.yml

@@ -24,7 +24,7 @@ jobs:
           components: rustfmt, clippy
 
       - name: Cache Rust dependencies
-        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v4
         with:
           path: |
             ~/.cargo/bin/