Create wallet canisters sequentially (#419)

# Motivation

Since `dfx` 0.24.1, creating the snapshot results in creating only 11 or
10 SNSes instead of 12 almost every time.
For example:
https://github.com/dfinity/snsdemo/actions/runs/11659664378/job/32460602932?pr=418

After debugging, I found out that creating wallet canisters as part of
the parallel SNS creation started occasionally failing with.
```
Error: Failed to setup wallet caller.
Caused by: Failed to create wallet
Caused by: Failed to load wallet configuration
Caused by: failed to parse contents of /home/runner/work/snsdemo/snsdemo/users/snsdemo_1/.local/share/dfx/network/local/wallets.json as json
Caused by: EOF while parsing a value at line 1 column 0
```

I'm not sure why but it might not work well anymore to create many
wallet canisters simultaneously.

Also, while I was debugging this it appears that MacOS-12 stopped being
supported on GitHub.

# Changes

1. Move the creating the snsdemo identities (which includes wallet
canister creation) outside the parallel process so that it is done
sequentially.
2. Check that we have the expected number of SNSes after SNS creation is
done.
3. Use MacOS 14 instead of MacOS 12.

---------

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

.github/workflows/run.yml

@@ -12,7 +12,7 @@ jobs:
   #    strategy:
   #      fail-fast: false
   #      matrix:
-  #        os: [ macos-12, ubuntu-22.04 ]
+  #        os: [ macos-14, ubuntu-22.04 ]
   #    steps:
   #      - name: Checkout
   #        uses: actions/checkout@v3
@@ -23,7 +23,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-12, ubuntu-22.04]
+        os: [macos-14, ubuntu-22.04]
     steps:
       - name: Checkout
         uses: actions/checkout@v3
@@ -32,7 +32,7 @@ jobs:
           echo "$HOME/.local/bin" >> $GITHUB_PATH
           echo "$PWD/bin" >> $GITHUB_PATH
       - name: Unbork mac
-        if: matrix.os == 'macos-12'
+        if: matrix.os == 'macos-14'
         run: |
           brew install bash
           echo "/usr/local/bin" >> $GITHUB_PATH
@@ -49,11 +49,11 @@ jobs:
           ./bin/dfx-sns-sale-buy
           ./bin/dfx-sns-sale-finalize
       - name: Create lots of SNS
-        if: matrix.os != 'macos-12'
+        if: matrix.os != 'macos-14'
         run: |
           ./bin/dfx-sns-demo-mksns-parallel -s 10 --config_index_offset 2 -m snsdemo8
       - name: Save state
-        if: matrix.os != 'macos-12'
+        if: matrix.os != 'macos-14'
         run: |
           # Stop the replica to let it persist all its state before we save the state.
           dfx stop
@@ -69,7 +69,7 @@ jobs:
           echo "Saving state"
           bin/dfx-snapshot-save --verbose --snapshot state.tar.xz
       - name: Upload state
-        if: matrix.os != 'macos-12'
+        if: matrix.os != 'macos-14'
         uses: actions/upload-artifact@v3
         with:
           name: snsdemo
@@ -81,7 +81,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-12, ubuntu-22.04]
+        os: [macos-14, ubuntu-22.04]
     steps:
       - name: Checkout
         uses: actions/checkout@v3
@@ -90,7 +90,7 @@ jobs:
           echo "$HOME/.local/bin" >> $GITHUB_PATH
           echo "$PWD/bin" >> $GITHUB_PATH
       - name: Unbork mac
-        if: matrix.os == 'macos-12'
+        if: matrix.os == 'macos-14'
         run: |
           brew install bash
           echo "/usr/local/bin" >> $GITHUB_PATH
@@ -115,6 +115,6 @@ jobs:
           ./bin/dfx-sns-sale-buy
           ./bin/dfx-sns-sale-finalize
       - name: Create lots of SNS
-        if: matrix.os != 'macos-12'
+        if: matrix.os != 'macos-14'
         run: |
           ./bin/dfx-sns-demo-mksns-parallel -s 10 --config_index_offset 2 -m snsdemo8

bin/dfx-sns-demo-mksns-parallel

@@ -73,10 +73,14 @@ create_all_sns() {
   PROCESSES=()
   echo "I am $$"
   for ((i = 0; i < NUM_SNS_TO_MAKE; i++)); do
+    # Creating wallet canisters in parallel started occasionally failing with
+    # 0.24.1. When creating 10 in parallel, almost always at least 1 would fail.
+    # So we create the users outside the background process.
+    DEMO_USER="snsdemo_$i"
+    make_user "$DEMO_USER"
     (
       echo "Starting $BASHPID"
       DEMO_USER="snsdemo_$i"
-      make_user "$DEMO_USER"
       become_user "$DEMO_USER"
 
       ./bin/dfx-sns-demo-mksns-config --config_index $((CONFIG_INDEX_OFFSET + i)) --unique_logo "$UNIQUE_LOGO"

bin/dfx-stock-deploy

@@ -49,6 +49,13 @@ if [ "${PARALLEL_SNS_COUNT:-0}" -gt 0 ]; then
   dfx-sns-demo-mksns-parallel --network "$DFX_NETWORK" --num_sns "$PARALLEL_SNS_COUNT" --majority snsdemo8 --config_index_offset 2 --unique_logo "$UNIQUE_LOGO"
 fi
 
+SNS_COUNT="$(dfx canister call nns-sns-wasm list_deployed_snses '(record{})' | idl2json | jq -r '.instances | length')"
+EXPECTED_SNS_COUNT="$((2 + PARALLEL_SNS_COUNT))"
+if [[ "$SNS_COUNT" != "$EXPECTED_SNS_COUNT" ]]; then
+  echo "❌ Expected $EXPECTED_SNS_COUNT SNSes. Found $SNS_COUNT"
+  exit 1
+fi
+
 : Set up ckbtc canisters
 dfx-ckbtc-import --prefix ckbtc_
 dfx-ckbtc-deploy --prefix ckbtc_ --network "$DFX_NETWORK" --yes