chore(ci)(deps): bump actions/cache from 4 to 5

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/fpga-build.yml

@@ -31,7 +31,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -86,7 +86,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -147,7 +147,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -256,7 +256,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -301,7 +301,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo + FPGA tools
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -417,7 +417,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -486,7 +486,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
 
       - name: Cache Cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry