fix keep-state not being respected

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

.github/workflows/ci.yml

@@ -621,6 +621,7 @@ jobs:
         uses: ./
         with:
           name: foo
+          keep-state: true
 
   keep-state-error:
     runs-on: ubuntu-latest

src/state-helper.ts

@@ -9,7 +9,7 @@ export const certsDir = process.env['STATE_certsDir'] || '';
 export const tmpDockerContext = process.env['STATE_tmpDockerContext'] || '';
 export const cleanup = /true/i.test(process.env['STATE_cleanup'] || '');
 export const buildxIsDefaultBuilder = /true/i.test(process.env['STATE_buildxIsDefaultBuilder'] || '');
-export const keepState = !!process.env['STATE_keepState'];
+export const keepState = /true/i.test(process.env['STATE_keepState'] || '');
 
 export function setDebug(debug: string) {
   core.saveState('isDebug', debug);
@@ -47,6 +47,6 @@ export function setBuildxIsDefaultBuilder(buildxIsDefaultBuilder: boolean) {
   core.saveState('buildxIsDefaultBuilder', buildxIsDefaultBuilder);
 }
 
-export function setKeepState(retain: boolean) {
-  core.saveState('keepState', retain);
+export function setKeepState(keepState: boolean) {
+  core.saveState('keepState', keepState);
 }