Chg UBC-MOAD/gha-workflows/ workflow pins to @main

If I can't trust myself, who can I trust?

But really, less maintenance when I have to update 3rd party action pins
in our reusable workflows.

.github/workflows/assign-issue-pr.yaml

@@ -13,4 +13,4 @@ jobs:
     permissions:
       issues: write
       pull-requests: write
-    uses: UBC-MOAD/gha-workflows/.github/workflows/auto-assign.yaml@39ab5bcb2c528cc2d1ad922c3b9f918087ef48ff
+    uses: UBC-MOAD/gha-workflows/.github/workflows/auto-assign.yaml@main

.github/workflows/codeql-analysis.yaml

@@ -17,6 +17,6 @@ jobs:
       fail-fast: false
       matrix:
         language: [ 'python' ]
-    uses: UBC-MOAD/gha-workflows/.github/workflows/codeql-analysis.yaml@73cd061e7d3c3cabc39cda291cb7bc9b95b7ab35
+    uses: UBC-MOAD/gha-workflows/.github/workflows/codeql-analysis.yaml@main
     with:
       language: ${{ matrix.language }}

.github/workflows/pytest-with-coverage.yaml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version: [ '3.10', '3.11' ]
-    uses: UBC-MOAD/gha-workflows/.github/workflows/pytest-with-coverage.yaml@73cd061e7d3c3cabc39cda291cb7bc9b95b7ab35
+    uses: UBC-MOAD/gha-workflows/.github/workflows/pytest-with-coverage.yaml@main
     with:
       python-version: ${{ matrix.python-version }}
       conda-env-file: envs/environment-test.yaml

.github/workflows/sphinx-linkcheck.yaml

@@ -16,7 +16,7 @@ jobs:
         # Need to specify Python version here because we use test env which gets its
         # Python version via matrix
         python-version: [ '3.11' ]
-    uses: UBC-MOAD/gha-workflows/.github/workflows/sphinx-linkcheck.yaml@a34def527ceee8686a208588e899f9837085215c
+    uses: UBC-MOAD/gha-workflows/.github/workflows/sphinx-linkcheck.yaml@main
     with:
       python-version: ${{ matrix.python-version }}
       conda-env-file: envs/environment-test.yaml