chore: revert the alpha version computation and change the required version in the sam test (#19573)

The [previous change](#19560) breaks `jsii-pacmak` with the message:

>Error: Unable to map prerelease identifier (in: 2.18.0-rc.0-alpha.0) to python, as sequence ‘0-alpha’ is not an integer

Going for a more conservative solution here: keep the versions as they are and just replace `rc` with `alpha` in the tests that need to install alpha versions.

----

### All Submissions:

* [ ] Have you followed the guidelines in our [Contributing guide?](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md)

### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/master/INTEGRATION_TESTS.md)?
	* [ ] Did you use `cdk-integ` to deploy the infrastructure and generate the snapshot (i.e. `cdk-integ` without `--dry-run`)?

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: otaviomacedo

packages/aws-cdk/test/integ/helpers/sam.ts

@@ -60,8 +60,8 @@ export function withSamIntegrationCdkApp<A extends TestContext & AwsContext>(blo
       } else {
         await installNpmPackages(fixture, {
           'aws-cdk-lib': installationVersion,
-          '@aws-cdk/aws-lambda-go-alpha': `${installationVersion}-alpha.0`,
-          '@aws-cdk/aws-lambda-python-alpha': `${installationVersion}-alpha.0`,
+          '@aws-cdk/aws-lambda-go-alpha': installationVersion.replace('rc', 'alpha'),
+          '@aws-cdk/aws-lambda-python-alpha': installationVersion.replace('rc', 'alpha'),
           'constructs': '^10',
         });
       }

tools/@aws-cdk/individual-pkg-gen/package.json

@@ -29,14 +29,12 @@
     "@aws-cdk/cdk-build-tools": "0.0.0",
     "@aws-cdk/pkglint": "0.0.0",
     "@types/fs-extra": "^8.1.2",
-    "@types/jest": "^27.4.1",
-    "@types/semver": "^7.3.9"
+    "@types/jest": "^27.4.1"
   },
   "dependencies": {
     "aws-cdk-migration": "0.0.0",
     "fs-extra": "^9.1.0",
-    "@lerna/project": "4.0.0",
-    "semver": "^7.3.5"
+    "@lerna/project": "4.0.0"
   },
   "keywords": [
     "aws",

tools/@aws-cdk/individual-pkg-gen/transform-packages.ts

@@ -1,7 +1,6 @@
 import * as path from 'path';
 import * as awsCdkMigration from 'aws-cdk-migration';
 import * as fs from 'fs-extra';
-import { SemVer, parse } from 'semver';
 // eslint-disable-next-line @typescript-eslint/no-require-imports
 const lerna_project = require('@lerna/project');
 // eslint-disable-next-line @typescript-eslint/no-require-imports
@@ -159,10 +158,7 @@ function transformPackageJson(pkg: any, source: string, destination: string, alp
 
   packageJson.name += '-alpha';
   if (ver.alphaVersion) {
-    // The -rc.0 suffix is used in the integration pipeline to distinguish candidate packages from real NPM packages, and needs to be retained
-    const rcSuffix = packageJson.version.endsWith('-rc.0') ? '-rc.0' : '';
-    const { major, minor, patch } = parse(packageJson.version) as SemVer;
-    packageJson.version = [major, minor, patch].join('.') + rcSuffix + '-alpha.0';
+    packageJson.version = ver.alphaVersion;
   }
   packageJson.repository.directory = `packages/individual-packages/${pkgUnscopedName}`;