CI: {caching, test, bench, flags}: ('' -> "")

Tripped-over the syntax highlighting & the DHall work (which uses `''` for QuasiQuoting stuff)

Author: Anton-Latukha

.github/workflows/bench.yml

@@ -89,11 +89,11 @@ jobs:
       continue-on-error: true
       run: |
         cabal v2-freeze && \
-        echo '' && \
+        echo "" && \
         echo 'Output:' && \
-        echo '' && \
+        echo "" && \
         cat 'cabal.project.freeze' && \
-        echo '' || \
+        echo "" || \
         echo 'WARNING: Could not produce the `freeze`.'
 
     - name: Hackage sources cache

.github/workflows/caching.yml

@@ -146,11 +146,11 @@ jobs:
         continue-on-error: true
         run: |
           cabal v2-freeze && \
-          echo '' && \
+          echo "" && \
           echo 'Output:' && \
-          echo '' && \
+          echo "" && \
           cat 'cabal.project.freeze' && \
-          echo '' || \
+          echo "" || \
           echo 'WARNING: Could not produce the `freeze`.'
 
       # 2021-12-02: NOTE: Cabal Hackage source tree storage does not depend on OS or GHC really,

.github/workflows/flags.yml

@@ -102,11 +102,11 @@ jobs:
         continue-on-error: true
         run: |
           cabal v2-freeze && \
-          echo '' && \
+          echo "" && \
           echo 'Output:' && \
-          echo '' && \
+          echo "" && \
           cat 'cabal.project.freeze' && \
-          echo '' || \
+          echo "" || \
           echo 'WARNING: Could not produce the `freeze`.'
 
       - name: Hackage sources cache

.github/workflows/test.yml

@@ -150,11 +150,11 @@ jobs:
         continue-on-error: true
         run: |
           cabal v2-freeze && \
-          echo '' && \
+          echo "" && \
           echo 'Output:' && \
-          echo '' && \
+          echo "" && \
           cat 'cabal.project.freeze' && \
-          echo '' || \
+          echo "" || \
           echo 'WARNING: Could not produce the `freeze`.'
 
       - name: Hackage sources cache