[BUG] check command logs a warning because a non fixed version of ink is set in templates dependencies

[ipapandinas]

Description

The ink version (4.2.1) used in contract templates do not come prefixed with a "=" or "v".
This logs the warning below when running swanky check command.

[WARNING]Some of the ink dependencies do not have a fixed version.
      This can lead to accidentally installing version higher than supported by the node.
      Please use "=" to install a fixed version (Example: "=3.0.1")

Then, this error occurs when adding the "=" prefix manually to the ink version in the Cargo.toml of the flipper contract template.

swanky check                 
✔ Check Rust
✔ Check cargo
✔ Check cargo nightly
✔ Check cargo dylint
✔ Check cargo-contract
✔ Read ink dependencies

error:   UnknownError: Invalid Version: =4.2.1
Please report this bug at: https:/swankyhub/swanky-cli/issues
    at new SemVer (~/Documents/dev/astar/swanky-cli/node_modules/semver/classes/semver.js:38:13)
    at compare (~/Documents/dev/astar/swanky-cli/node_modules/semver/functions/compare.js:3:3)
    at Object.gt (~/Documents/dev/astar/swanky-cli/node_modules/semver/functions/gt.js:2:29)
    at file://~/Documents/dev/astar/swanky-cli/dist/commands/check/index.js:79:51
    at Array.forEach (<anonymous>)
    at Task.task [as taskFn] (file://~/Documents/dev/astar/swanky-cli/dist/commands/check/index.js:76:60)
    at Task.run (file://~/Documents/dev/astar/swanky-cli/node_modules/listr2/dist/index.js:1956:35)

To fix

• Set fixed version on all contract templates dependencies.
• Adjust the "Verify ink version" task to support "=" prefix.
• Remove version.startsWith("v") since it is not a valid Rust prefix.

Steps to Reproduce

1. swanky init test
2. cd test
3. swanky check

Expected vs. Actual Behavior

Expected: No warning logged.
Actual Behavior: Warning logged.

Environment

• Operating system: Mac M1 darwin
• Project version/tag: @astar-network/swanky-cli/3.1.0 darwin-arm64 node-v18.17.1
• Rust version: rustc 1.72.1
• Rust toolchain: 1.72-aarch64-apple-darwin
• Node version: 18.17.1