fix(input-number): restore decimal input mode default (#9741)

**Related Issue:** #9740

## Summary

Restores `decimal` default for the internal input's `inputmode`, which
was unintentionally removed in
#9123.

packages/calcite-components/src/components/input-number/input-number.e2e.ts

@@ -1818,4 +1818,34 @@ describe("calcite-input-number", () => {
     expect(await input.getProperty("value")).toBe(`${totalNudgesUp}`);
     expect(calciteInputNumberInput).toHaveReceivedEventTimes(totalNudgesUp);
   });
+
+  it("should have decimal as initial inputmode", async () => {
+    const page = await newE2EPage();
+    await page.setContent(`<calcite-input-number></calcite-input-number>`);
+    const inputNumber = await page.find("calcite-input-number");
+    const internalInput = await page.find("calcite-input-number >>> input");
+
+    // we assert on the attribute as this is what browsers will look for to display the correct keyboard
+    expect(internalInput.getAttribute("inputmode")).toBe("decimal");
+
+    inputNumber.setProperty("inputMode", "text");
+    await page.waitForChanges();
+
+    expect(internalInput.getAttribute("inputmode")).toBe("text");
+
+    inputNumber.setProperty("inputMode", "");
+    await page.waitForChanges();
+
+    expect(internalInput.getAttribute("inputmode")).toBe("decimal");
+
+    inputNumber.setAttribute("inputmode", "none");
+    await page.waitForChanges();
+
+    expect(internalInput.getAttribute("inputmode")).toBe("none");
+
+    inputNumber.setAttribute("inputmode", "");
+    await page.waitForChanges();
+
+    expect(internalInput.getAttribute("inputmode")).toBe("decimal");
+  });
 });

packages/calcite-components/src/components/input-number/input-number.tsx

@@ -1087,7 +1087,7 @@ export class InputNumber
         defaultValue={this.defaultValue}
         disabled={this.disabled ? true : null}
         enterKeyHint={this.el.enterKeyHint || this.el.getAttribute("enterkeyhint")}
-        inputMode={this.el.inputMode || this.el.getAttribute("inputmode")}
+        inputMode={this.el.inputMode || this.el.getAttribute("inputmode") || "decimal"}
         key="localized-input"
         maxLength={this.maxLength}
         minLength={this.minLength}