ci: upgrade to using actions/{up,down}load-artifacts v2

The GitHub Actions to upload/download workflow artifacts saw a major
upgrade since Git's GitHub workflow was established. Let's use it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

.github/workflows/main.yml

@@ -90,7 +90,7 @@ jobs:
         NO_PERL: 1
       run: ci/make-test-artifacts.sh artifacts
     - name: upload build artifacts
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v2
       with:
         name: windows-artifacts
         path: artifacts
@@ -104,7 +104,7 @@ jobs:
     steps:
     - uses: actions/checkout@v1
     - name: download build artifacts
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v2
       with:
         name: windows-artifacts
         path: ${{github.workspace}}
@@ -121,7 +121,7 @@ jobs:
       run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v2
       with:
         name: failed-tests-windows
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -170,7 +170,7 @@ jobs:
         mkdir -p artifacts &&
         eval "$(make -n artifacts-tar INCLUDE_DLLS_IN_ARTIFACTS=YesPlease ARTIFACTS_DIRECTORY=artifacts 2>&1 | grep ^tar)"
     - name: upload build artifacts
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v2
       with:
         name: vs-artifacts
         path: artifacts
@@ -185,7 +185,7 @@ jobs:
     - uses: actions/checkout@v1
     - uses: git-for-windows/setup-git-for-windows-sdk@v1
     - name: download build artifacts
-      uses: actions/download-artifact@v1
+      uses: actions/download-artifact@v2
       with:
         name: vs-artifacts
         path: ${{github.workspace}}
@@ -204,7 +204,7 @@ jobs:
       run: ci/print-test-failures.sh
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v2
       with:
         name: failed-tests-windows
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -242,7 +242,7 @@ jobs:
       if: failure()
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v2
       with:
         name: failed-tests-${{matrix.vector.jobname}}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
@@ -269,7 +269,7 @@ jobs:
       if: failure()
     - name: Upload failed tests' directories
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
-      uses: actions/upload-artifact@v1
+      uses: actions/upload-artifact@v2
       with:
         name: failed-tests-${{matrix.vector.jobname}}
         path: ${{env.FAILED_TEST_ARTIFACTS}}