ci: do not fail codecov action if error (#2044)

Author: jeffydc

.github/workflows/hvd-tests.yml

@@ -70,4 +70,4 @@ jobs:
         with:
           file: ./coverage.xml
           flags: hvd-cpu
-          fail_ci_if_error: true
+          fail_ci_if_error: false

.github/workflows/tpu-tests.yml

@@ -86,4 +86,4 @@ jobs:
         with:
           file: ./coverage.xml
           flags: tpu
-          fail_ci_if_error: true
+          fail_ci_if_error: false

.github/workflows/unit-tests.yml

@@ -114,7 +114,7 @@ jobs:
         with:
           file: ./coverage.xml
           flags: cpu
-          fail_ci_if_error: true
+          fail_ci_if_error: false
 
       - name: Run MNIST Examples
         shell: bash -l {0}