fix: Replace Circle CI with Github actions

* Update copyright headers
* Add lint, semgrep, snyk
* Produce and manage NOTICE files
* Remove use of poetry-dynamic-versioning 
* Keep pyproject.toml file up to date with the correct version
* Use "beta" version marker for pep440 on develop branch

.github/dependabot.yml

@@ -1,7 +1,5 @@
 ##
-## SPDX-FileCopyrightText: 2020 Splunk, Inc. <sales@splunk.com>
-## SPDX-License-Identifier: Apache-2.0
-##
+####
 ##
 version: 2
 updates:

.github/workflows/agreements.yaml

@@ -0,0 +1,58 @@
+name: "CLA Assistant"
+on:
+  issue_comment:
+    types: [created]
+  pull_request_target:
+    types: [opened, closed, synchronize]
+
+jobs:
+  ContributorLicenseAgreement:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "CLA Assistant"
+        if: (github.event.comment.body == 'recheck' || github.event.comment.body == 'I have read the CLA Document and I hereby sign the CLA') || github.event_name == 'pull_request_target'
+        # Alpha Release
+        uses: cla-assistant/github-action@v2.3.1-beta
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # the below token should have repo scope and must be manually added by you in the repository's secret
+          PERSONAL_ACCESS_TOKEN: ${{ secrets.PAT_CLATOOL }}
+        with:
+          path-to-signatures: "signatures/version1/cla.json"
+          path-to-document: "https://github.com/splunk/cla-agreement/blob/main/CLA.md" # e.g. a CLA or a DCO document
+          # branch should not be protected
+          branch: "main"
+          allowlist: dependabot
+          #below are the optional inputs - If the optional inputs are not given, then default values will be taken
+          remote-organization-name: splunk
+          remote-repository-name: cla-agreement
+          #create-file-commit-message: 'For example: Creating file for storing CLA Signatures'
+          #signed-commit-messag e: 'For example: $contributorName has signed the CLA in #$pullRequestNo'
+          #custom-notsigned-prcomment: 'pull request comment with Introductory message to ask new contributors to sign'
+          #custom-pr-sign-comment: 'The signature to be committed in order to sign the CLA'
+          #custom-allsigned-prcomment: 'pull request comment when all contributors has signed, defaults to **CLA Assistant Lite bot** All Contributors have signed the CLA.'
+  CodeOfConduct:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "COC Assistant"
+        if: (github.event.comment.body == 'recheck' || github.event.comment.body == 'I have read the Code of Conduct and I hereby accept the Terms') || github.event_name == 'pull_request_target'
+        # Alpha Release
+        uses: cla-assistant/github-action@v2.3.1-beta
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # the below token should have repo scope and must be manually added by you in the repository's secret
+          PERSONAL_ACCESS_TOKEN: ${{ secrets.PAT_CLATOOL }}
+        with:
+          path-to-signatures: "signatures/version1/coc.json"
+          path-to-document: "https://github.com/splunk/cla-agreement/blob/main/CODE_OF_CONDUCT.md" # e.g. a COC or a DCO document
+          # branch should not be protected
+          branch: "main"
+          allowlist: dependabot
+          #below are the optional inputs - If the optional inputs are not given, then default values will be taken
+          remote-organization-name: splunk
+          remote-repository-name: cla-agreement
+          custom-pr-sign-comment: "I have read the Code of Conduct and I hereby accept the Terms"
+          create-file-commit-message: "For example: Creating file for storing COC Signatures"
+          signed-commit-message: "$contributorName has signed the COC in #$pullRequestNo"
+          custom-notsigned-prcomment: "All contributors have NOT signed the COC Document"
+          custom-allsigned-prcomment: "****CLA Assistant Lite bot**** All contributors have signed the COC  ✍️ ✅"