feat: remove iogx

ETCM-8233

iogx is unnecessarily complex for our use cases. nosys essentially only handles
systems for you, rewriting the outputs. As such, it also fixes interfaces lik  e
'nix flake show' where Input From Derivation (haskell.nix) would usually break
the interface.

Other changes:

- Shells made into a single shell
- Updated nixci to omnix
- Cleanup outputs

.github/workflows/ci.yml

@@ -25,8 +25,9 @@ jobs:
       - name: Add signing key for nix
         run: echo "${{ secrets.NIX_SIGNING_KEY }}" > "${{ runner.temp }}/nix-key"
 
-      - name: Run nixci to build all outputs
-        run: nix run github:srid/nixci -- -v build -- --fallback > ${{ runner.temp }}/outputs
+      - name: Run omnix to build all outputs
+        run: |
+          nix run github:juspay/omnix -- ci -v > ${{ runner.temp }}/outputs
 
       - name: Acquire AWS credentials
         uses: aws-actions/configure-aws-credentials@v4
@@ -54,7 +55,10 @@ jobs:
         with:
           token: ${{ github.token }}
       - name: Run tests
-        run: nix build .#check.x86_64-linux -L --fallback
+        run: |
+          nix build .#check.x86_64-linux.pre-commit-check -L --fallback
+          nix build .#check.x86_64-linux.upToDatePlutusScriptCheck -L --fallback
+          nix build .#check.x86_64-linux.partner-chains-smart-contracts -L --fallback
 
   build-arm64-darwin:
     permissions:
@@ -70,10 +74,9 @@ jobs:
       - name: Add signing key for nix
         run: echo "${{ secrets.NIX_SIGNING_KEY }}" > "${{ runner.temp }}/nix-key"
 
-      - name: Run nixci to build all outputs
+      - name: Run omnix to build all outputs
         run: |
-          nix run github:srid/nixci -- -v build -- --fallback > ${{ runner.temp }}/outputs
-
+          nix run github:juspay/omnix -- ci -v > ${{ runner.temp }}/outputs
       - name: Acquire AWS credentials
         uses: aws-actions/configure-aws-credentials@v4
         with:
@@ -101,4 +104,6 @@ jobs:
           token: ${{ github.token }}
       - name: Run tests
         run: |
-          nix build .#check.aarch64-darwin -L --fallback
+          nix build .#check.aarch64-darwin.pre-commit-check -L --fallback
+          nix build .#check.aarch64-darwin.upToDatePlutusScriptCheck -L --fallback
+          nix build .#check.aarch64-darwin.partner-chains-smart-contracts -L --fallback