Update the GitHub actions versions

Nothing sparks more joy than things that worked previously suddenly
refusing to work because it's more than a year old.

.github/workflows/build.yml

@@ -28,7 +28,7 @@ jobs:
     name: Package plugin binaries
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Fetch all git history
         run: git fetch --force --prune --tags --unshallow
 
@@ -38,7 +38,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y libasound2-dev libgl-dev libjack-dev libx11-xcb-dev  libxcb1-dev libxcb-dri2-0-dev libxcb-icccm4-dev libxcursor-dev libxkbcommon-dev libxcb-shape0-dev libxcb-xfixes0-dev
 
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         # FIXME: Caching `target/` causes the Windows runner to blow up after some time
         if: startsWith(matrix.os, 'windows')
         with:
@@ -47,7 +47,7 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
           key: ${{ matrix.name }}-${{ matrix.cross-target }}
-      - uses: actions/cache@v3
+      - uses: actions/cache@v4
         if: "!startsWith(matrix.os, 'windows')"
         with:
           path: |
@@ -98,7 +98,7 @@ jobs:
           mv target/bundled/* "$ARCHIVE_NAME/$ARCHIVE_NAME"
       - name: Add an OS-specific readme file with installation instructions
         run: cp ".github/workflows/readme-${{ runner.os }}.txt" "$ARCHIVE_NAME/$ARCHIVE_NAME/README.txt"
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           name: ${{ env.ARCHIVE_NAME }}
           path: ${{ env.ARCHIVE_NAME }}