Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/cmake.yml

@@ -50,7 +50,7 @@ jobs:
       run: sudo apt-get install libsndfile1-dev libjson-c-dev libvolk2-dev libfftw3-dev soapysdr-module-all libsoapysdr-dev libxml2-dev portaudio19-dev
 
     - name: Checkout (sigutils)
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         repository: BatchDrake/sigutils
         ref: ${{needs.dep_target.outputs.target_ref}}
@@ -71,7 +71,7 @@ jobs:
       run: sudo cmake --build ${{github.workspace}}/sigutils/build --config ${{env.BUILD_TYPE}} --target install
 
     - name: Checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         path: suscan
         submodules: recursive
@@ -143,7 +143,7 @@ jobs:
         cd ../..
 
     - name: Checkout (sigutils)
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         repository: BatchDrake/sigutils
         ref: ${{needs.dep_target.outputs.target_ref}}
@@ -163,7 +163,7 @@ jobs:
       run: sudo cmake --build ${{github.workspace}}/sigutils/build --config ${{env.BUILD_TYPE}} --target install
 
     - name: Checkout (suscan)
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
       with:
         path: suscan
         submodules: recursive
@@ -191,7 +191,7 @@ jobs:
           install: git mingw-w64-x86_64-cc mingw-w64-x86_64-make mingw-w64-x86_64-cmake mingw-w64-x86_64-libsndfile mingw-w64-x86_64-fftw mingw-w64-x86_64-volk mingw-w64-x86_64-libxml2 mingw-w64-x86_64-libusb
 
       - name: Checkout (sigutils)
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: BatchDrake/sigutils
           ref: ${{needs.dep_target.outputs.target_ref}}
@@ -210,7 +210,7 @@ jobs:
 
       # SoapySDR
       - name: Checkout (soapysdr)
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: pothosware/SoapySDR
           ref: refs/heads/master
@@ -227,7 +227,7 @@ jobs:
 
       # BatchDrake's fixed rtl-sdr
       - name: Checkout (rtl-sdr-blog)
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: BatchDrake/rtl-sdr-blog
           ref: refs/heads/feature/xfer-completion
@@ -244,7 +244,7 @@ jobs:
 
       # SoapyRTLSDR
       - name: Checkout (soapyrtlsdr)
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: pothosware/SoapyRTLSDR
           ref: refs/heads/master
@@ -261,7 +261,7 @@ jobs:
 
       # suscan
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: true
           fetch-depth: 0