To prevent new secret scanning alerts, enable push protection to block secrets from being committed in the first place, and manage push protection patterns to disable blocking for specific, low-risk secret types or false positives.
Enable Push Protection
Prevent new commits: Push protection proactively scans code for secrets before they are pushed to a repository. If a secret is detected, the push is blocked, providing immediate feedback to developers and preventing secrets from entering the codebase.
Configure patterns: You can configure which secret patterns are blocked at the organization or enterprise level. By disabling patterns that frequently generate false positives, you can reduce the number of new alerts.

When Dependabot detects vulnerable dependencies in your repositories, we generate a Dependabot alert and display it on the Security tab for the repository. GitHub notifies the maintainers of affected repositories about the new alert according to their notification preferences.
Dependabot is enabled by default on all public repositories, and needs to be enabled on private repositories.
Note:
By default, no repositories receive Dependabot alerts unless configuration is explicitly enabled.
GitHub does not enable Dependabot alerts automatically for any repositories unless:
The feature is turned on manually
It's configured at the organization or enterprise level via security policies This includes public, private, and enterprise-owned repositories -manual activation is required.

You can find security alerts from Dependabot, Secret scanning, and Code scanning under your repository's Security tab.

The options available to specify the additional queries you want to run are:
packs to install one or more CodeQL query packs and run the default query suite or queries for those packs.
queries to specify a single .ql file, a directory containing multiple .ql files, a .qls query suite definition file, or any combination.

If your workflow uses a language matrix, autobuild attempts to build each of the compiled languages listed in the matrix. Without a matrix autobuild attempts to build the supported compiled language that has the most source files in the repository. With the exception of Go, analysis of other compiled languages in your repository will fail unless you supply explicit build commands.
Note:
CodeQL build modes
The CodeQL action supports three different build modes for compiled languages:
none - the CodeQL database is created directly from the codebase without building the codebase (supported for all interpreted languages, and additionally supported for C/C++, C# and Java).
autobuild - CodeQL detects the most likely build method and uses this to attempt to build the codebase and create a database for analysis (supported for all compiled languages).
manual - you define the build steps to use for the codebase in the workflow (supported for all compiled languages, except Rust).