CI: {caching, test, bench}: m v2-update unification

Author: Anton-Latukha

.github/workflows/bench.yml

@@ -118,7 +118,8 @@ jobs:
               ${{ env.cache-name }}-${{ runner.os }}-${{ matrix.ghc }}-
               ${{ env.cache-name }}-${{ runner.os }}-
 
-    - run: cabal update
+    - run: |
+        cabal v2-update
 
     # max-backjumps is increased as a temporary solution
     # for dependency resolution failure

.github/workflows/caching.yml

@@ -184,7 +184,7 @@ jobs:
 
       - if: steps.compiled-deps.outputs.cache-hit != 'true'
         run: |
-          cabal update
+          cabal v2-update
 
       - if: steps.compiled-deps.outputs.cache-hit != 'true'
         name: Download all sources

.github/workflows/test.yml

@@ -179,7 +179,8 @@ jobs:
                 ${{ env.cache-name }}-${{ runner.os }}-${{ matrix.ghc }}-
                 ${{ env.cache-name }}-${{ runner.os }}-
 
-      - run: cabal v2-update
+      - run: |
+          cabal v2-update
 
       # repeating builds to workaround segfaults in windows and ghc-8.8.4
       - name: Build