chore(cicd): Update cache action version to v2.1.4

Author: S-Coyle

.github/workflows/master.yml

@@ -38,7 +38,7 @@ jobs:
 
       # Cache.
       - name: Cargo cache registry, index and build
-        uses: actions/cache@v2
+        uses: actions/cache@v2.1.4
         with:
           path: |
             ~/.cargo/registry

.github/workflows/pr.yml

@@ -31,7 +31,7 @@ jobs:
 
       # Cache.
       - name: Cargo cache registry, index and build
-        uses: actions/cache@v2
+        uses: actions/cache@v2.1.4
         with:
           path: |
             ~/.cargo/registry
@@ -70,7 +70,7 @@ jobs:
 
       # Cache.
       - name: Cargo cache registry, index and build
-        uses: actions/cache@v2
+        uses: actions/cache@v2.1.4
         with:
           path: |
             ~/.cargo/registry
@@ -141,7 +141,7 @@ jobs:
 
       # Cache.
       - name: Cargo cache registry, index and build
-        uses: actions/cache@v2
+        uses: actions/cache@v2.1.4
         with:
           path: |
             ~/.cargo/registry