ci: bump git-for-windows/setup-git-for-windows-sdk from v1 to v2

The v1 of `git-for-windows/setup-git-for-windows-sdk` runs on
Node.js 20, which GitHub is phasing out of the Actions runners.
v2 moves the action to Node.js 24 so that the CI jobs relying on
a Git for Windows SDK keep working once Node.js 20 is removed.

The risk is very low: v2 contains no functional changes to the
SDK setup itself, only the runtime upgrade. The action still
provisions the same minimal SDK and exposes the same outputs.
The sole precondition is a recent Actions Runner (>= 2.327.1),
which the github.com-hosted runners already satisfy.

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

.github/workflows/coverity.yml

@@ -41,7 +41,7 @@ jobs:
       - uses: actions/checkout@v6
       - name: install minimal Git for Windows SDK
         if: contains(matrix.os, 'windows')
-        uses: git-for-windows/setup-git-for-windows-sdk@v1
+        uses: git-for-windows/setup-git-for-windows-sdk@v2
       - run: ci/install-dependencies.sh
         if: contains(matrix.os, 'ubuntu') || contains(matrix.os, 'macos')
         env:

.github/workflows/main.yml

@@ -113,7 +113,7 @@ jobs:
       cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: actions/checkout@v6
-    - uses: git-for-windows/setup-git-for-windows-sdk@v1
+    - uses: git-for-windows/setup-git-for-windows-sdk@v2
     - name: build
       shell: bash
       env:
@@ -147,7 +147,7 @@ jobs:
     - name: extract tracked files and build artifacts
       shell: bash
       run: tar xf artifacts.tar.gz && tar xf tracked.tar.gz
-    - uses: git-for-windows/setup-git-for-windows-sdk@v1
+    - uses: git-for-windows/setup-git-for-windows-sdk@v2
     - name: test
       shell: bash
       run: . /etc/profile && ci/run-test-slice.sh $((${{matrix.nr}} + 1)) 10
@@ -174,7 +174,7 @@ jobs:
       cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
     - uses: actions/checkout@v6
-    - uses: git-for-windows/setup-git-for-windows-sdk@v1
+    - uses: git-for-windows/setup-git-for-windows-sdk@v2
     - name: initialize vcpkg
       uses: actions/checkout@v6
       with:
@@ -224,7 +224,7 @@ jobs:
       group: vs-test-${{ matrix.nr }}-${{ github.ref }}
       cancel-in-progress: ${{ needs.ci-config.outputs.skip_concurrent == 'yes' }}
     steps:
-    - uses: git-for-windows/setup-git-for-windows-sdk@v1
+    - uses: git-for-windows/setup-git-for-windows-sdk@v2
     - name: download tracked files and build artifacts
       uses: actions/download-artifact@v8
       with: