Updates dependencies to new major version

[milanholemans]

Updates dependencies to the latest major version. Due to some new TypeScript rules, I had to refactor quite a few files.

[Copilot]

Pull request overview

This PR updates major dependency versions — primarily @azure/msal-common (v15→v16), @azure/msal-node (v3→v5), eslint (v9→v10), and c8 (v10→v11) — and refactors TypeScript source files to address new strictness requirements introduced by the upgraded tooling.

Changes:

• Dependency version bumps in package.json and npm-shrinkwrap.json
• ESLint configuration and custom rule API updates for ESLint 10 compatibility
• Widespread refactoring of TypeScript code: replacing let x = '' / let x = null / let x = undefined with uninitialized declarations or const where variables are only assigned once

Reviewed changes

Copilot reviewed 67 out of 68 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
package.json / npm-shrinkwrap.json	Major version bumps for MSAL, ESLint, c8, and related packages
src/Auth.ts	Updates clientApplication type from Msal.ClientApplication to union of concrete MSAL v5 types
src/cli/cli.ts	Adds no-unassigned-vars ESLint disable comments for module-level variables
eslint.config.mjs	Adds 'preserve-caught-error': 'off' to disable a rule; configures ESLint 10
eslint-rules/lib/rules/*.js	Migrates from deprecated context.getSourceCode()/context.getFilename() to context.sourceCode/context.filename
src/utils/urlUtil.ts	Removes now-unnecessary intermediate mutations of webRelativePath in getWebRelativePath
src/utils/spo.ts, src/utils/odata.ts, src/utils/powerPlatform.ts	Refactors variable declarations from empty initializers to uninitialized or const
src/m365/spo/commands/site/site-set.ts	Removes post-increment from last propertyId use in payload chain
src/m365/spo/commands/page/page-section-add.ts	Removes redundant post-increment from last sectionIndex push per template case
src/m365/spo/commands/page/page-*.ts (multiple)	Scopes variables more tightly using const and removes empty initializers
src/m365/spfx/commands/project/project-upgrade/rules/FN003003_CFG_bundles.ts	Removes unused index parameter from tryGetBundleName
Multiple other command files	Consistent let x = '' → uninitialized or const refactoring

Files not reviewed (1)

• npm-shrinkwrap.json: Language not supported

[MartinM85]

Hi @milanholemans, could you please resolve the conflicts?

[Copilot]

Pull request overview

Copilot reviewed 67 out of 68 changed files in this pull request and generated no new comments.

Files not reviewed (1)

• npm-shrinkwrap.json: Language not supported

[Jwaegebaert]

LGTM!!