Rely on local env varibale instead of context

We have this env varible set in the project settings as well as the
CircleCI context. Due to what seems like a bug on CircleCI's eng, the
using the context causes our release flow to halt when some member of
the team initiate releases, but not others. So for now, it's safest to
rely on the project settings, which definitely won't cause this issue.

.circleci/config.yml

@@ -1144,8 +1144,6 @@ workflows:
                 - /^v\d+\.\d+\.\d+(-rc\d+)?$/
       - release:
           name: "Release"
-          context:
-            - filecoin-goreleaser-key
           requires:
             - "Build ( darwin / amd64 )"
             - "Build ( linux / amd64 )"
@@ -1159,8 +1157,6 @@ workflows:
                 - /^v\d+\.\d+\.\d+(-rc\d+)?$/
       - release:
           name: "Release (dry-run)"
-          context:
-            - filecoin-goreleaser-key
           dry-run: true
           requires:
             - "Build ( darwin / amd64 )"

.circleci/template.yml

@@ -839,8 +839,6 @@ workflows:
                 - /^v\d+\.\d+\.\d+(-rc\d+)?$/
       - release:
           name: "Release"
-          context:
-            - filecoin-goreleaser-key
           requires:
             - "Build ( darwin / amd64 )"
             - "Build ( linux / amd64 )"
@@ -854,8 +852,6 @@ workflows:
                 - /^v\d+\.\d+\.\d+(-rc\d+)?$/
       - release:
           name: "Release (dry-run)"
-          context:
-            - filecoin-goreleaser-key
           dry-run: true
           requires:
             - "Build ( darwin / amd64 )"