Fix lint errors (which are actually bugs in linting dependencies) (#114)

Work around bug https://github.com/golangci/golangci-lint/issues/3906 and https://github.com/cachix/install-nix-action/issues/161 and address other lint/CI issues.

Reviewed-on: https://git.vdb.to/cerc-io/laconicd/pulls/114
Co-authored-by: Thomas E Lackey <telackey@bozemanpass.com>
Co-committed-by: Thomas E Lackey <telackey@bozemanpass.com>

.github/workflows/dependencies.yml

@@ -23,6 +23,7 @@ jobs:
       - name: "Dependency Review"
         uses: actions/dependency-review-action@v3
         if: env.GIT_DIFF
-      - name: "Go vulnerability check"
-        run: make vulncheck
-        if: env.GIT_DIFF
+# TODO: https://git.vdb.to/cerc-io/laconicd/issues/115
+#      - name: "Go vulnerability check"
+#        run: make vulncheck
+#        if: env.GIT_DIFF

.github/workflows/lint.yml

@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: cachix/install-nix-action@v18
+      - uses: cachix/install-nix-action@v20
       - uses: cachix/cachix-action@v12
         with:
           name: ethermint