CI: Fix failing CI jobs

.github/workflows/ci.yml

@@ -166,6 +166,16 @@ jobs:
         uses: actions/download-artifact@v3
         with:
           name: gem-${{ matrix.platform }}
+      - name: Update rubygems - ruby-2.6 to 2.7
+        if: matrix.ruby == '2.6' || matrix.ruby == '2.7'
+        run: |
+          gem install --no-doc rubygems-update -v 3.4.22
+          update_rubygems
+      - name: Update rubygems - ruby-2.5
+        if: matrix.ruby == '2.5'
+        run: |
+          gem install --no-doc rubygems-update -v 3.3.27
+          update_rubygems
       - name: Install gem-${{matrix.platform}}
         run: gem install --local *.gem --verbose
       - name: Run tests
@@ -174,7 +184,7 @@ jobs:
           ruby -rffi -S rake test
 
   job_fat_binary_multiarch:
-    name: multiarch (${{matrix.platform}} on ${{matrix.from_image}})
+    name: multiarch (${{matrix.platform}} on ${{matrix.from_image}} ${{matrix.image_platform}})
     needs: rcd_build
     strategy:
       fail-fast: false
@@ -197,7 +207,7 @@ jobs:
             gem_platform: x86-linux-musl
             dockerfile: alpine
           - from_image: alpine
-            image_platform: linux/arm32v6
+            image_platform: linux/arm/v6
             gem_platform: arm-linux-musl
             dockerfile: alpine