try containerized ci (+3 squashed commit)

Squashed commit:

[f0600744] troubleshooting

[fe11073c] cap auto threads at 32 due to diminishing returns

[0c7f8a1d] troubleshooting

.github/workflows/kcpp-build-release-linux.yaml

@@ -23,7 +23,16 @@ jobs:
         run: |
           apt-get update
           apt-get install -y sudo
-          sudo apt-get -y install git curl bzip2
+          export DEBIAN_FRONTEND=noninteractive
+          sudo ln -fs /usr/share/zoneinfo/UTC /etc/localtime
+          echo "tzdata tzdata/Areas select Etc" | sudo debconf-set-selections
+          echo "tzdata tzdata/Zones/Etc select UTC" | sudo debconf-set-selections
+          sudo apt-get -y install git curl bzip2 python3-tk tcl tk
+
+      - name: Set Tcl/Tk Paths
+        run: |
+          echo "TCL_LIBRARY=$(find /usr/lib/ -name 'tcl8*' | head -n 1)" >> $GITHUB_ENV
+          echo "TK_LIBRARY=$(find /usr/lib/ -name 'tk8*' | head -n 1)" >> $GITHUB_ENV
 
       - name: Build
         id: make_build