CI: workflows: disable stack where it is not used

Hopefully it would remove it & its files from being cached in the action. & also
not includde into environment.

Author: Anton-Latukha

.github/workflows/build.yml

@@ -33,6 +33,7 @@ jobs:
       with:
         ghc-version  : ${{ matrix.ghc   }}
         cabal-version: ${{ matrix.cabal }}
+        enable-stack: false
 
     # some alpines come with integer-simple instead of integer-gmp
     - name: Force integer-simple

.github/workflows/caching.yml

@@ -69,6 +69,7 @@ jobs:
         with:
           ghc-version: ${{ matrix.ghc }}
           cabal-version: ${{ matrix.cabal }}
+          enable-stack: false
 
       - if: runner.os == 'Windows'
         name: (Windows) Platform config

.github/workflows/hackage.yml

@@ -52,6 +52,7 @@ jobs:
         with:
           ghc-version  : ${{ matrix.ghc   }}
           cabal-version: ${{ matrix.cabal }}
+          enable-stack: false
 
       - name: Cache Cabal
         uses: actions/cache@v2

.github/workflows/test.yml

@@ -79,6 +79,7 @@ jobs:
         with:
           ghc-version  : ${{ matrix.ghc   }}
           cabal-version: ${{ matrix.cabal }}
+          enable-stack: false
 
       - if: runner.os == 'Windows'
         name: (Windows) Platform config